These are the Invocations favored by the Radiant and Twilight Queens.
Favored by Diamonds
Acqua applies at no cost when the target of a Princess' Charm is water or ice, and when she has spent at least one turn studying her target during the scene, and nothing significant has happened to it since. It also applies without cost when a Princess intends to teach someone, to master a body of knowledge, to prove or refute a theory, to discover things previously unknown to anyone, and to carry out a strategy she has previously formulated.
The Invocation aids only those who are open and candid in all their dealings. A Princess who deceives another person in any fashion, be it simple falsehood, sophistry, or material omission, cannot apply Acqua for the rest of the scene, unless the deception is necessary to shield an innocent from harm, or to keep a secret given her in confidence. A Princess may reserve what she knows, if it isn't relevant and no one asks her to inform them, and apply Acqua; she may not, however, cause another to believe what is untrue.
Favored by Spades
Aria applies at no cost when a Princess is blown by strong winds, moves at running speed or faster, or is at risk of falling from a height; and when the target of her Charm is the air, or other gases. It also applies without cost when a Princess intends to catch someone by surprise, to make someone laugh, to cast doubts, to expose pretensions and humiliate arrogance, and to subvert formal rules of an organisation or society.
Aria will not support any assertion of authority over another person. A Princess is free to advise, to persuade, to appeal to friendship, and even to deceive (within the limits of Belief) while using Aria, but if she issues a command she cannot apply the Invocation for the rest of the scene.
Favored by Swords
Fuoco applies at no cost when the target of a Princess' Charm is a flame, on fire, or hot enough to burn; and when the target is someone or something the Princess loves. It also applies without cost when a Princess intends to aid a person she loves, to strike at enemies with her full force, to take great risks for great gains, to inspire others to heroic endeavors, and at the culmination of a major campaign.
The Invocation abandons Princesses who abandon their beloved. A Princess who betrays or otherwise injures a person she loves or has loved cannot apply Fuoco until the one she has hurt forgives her for the injury, or until a full lunar month has passed.
Favored by Clubs
Legno applies at no cost when the target of a Princess' Charm is a living plant or wood, and when her Charm's target is a natural, non-sapient animal. It also applies without cost when a Princess intends to restore things to their natural state, to restrain the reckless and calm the fearful, to defend another from harm, to conserve and cultivate over time, and to influence without drawing attention to herself.
Those who would make use of Legno must live for harmony in all things. A Princess who attempts violence against someone not involved in combat, or who helps another to do so, may not apply the Invocation until the next sunrise. Self-defense, protecting a non-combatant, and using Charms to stop a fight without violence are unexceptionable, but if a Princess gives tactical support to an ally and the ally attacks one who has not begun to fight, she loses access to Legno just as if she had struck the blow herself.
Favored by Hearts
Terra applies at no cost when the target of a Princess' Charm is earth or stone, including all forms of gemstones; and when her target is a non-supernatural human being who gives informed consent to the Charm. It also applies without cost when a Princess intends to resolve a conflict without violence, to make someone or something beautiful, to give requested aid without expecting any return, to coordinate the efforts of several people in a project, or to help a lawful authority in their mandated duties.
Terra requires both decorum and consideration for others. A Princess who is rude or insensitive to another person without cause, or who knowingly breaks a rule of formal etiquette, cannot apply the Invocation for the rest of the scene.
Favored by Tears
Lacrima applies at no cost when a Princess touches a ghost's anchor, or is within Alhambra or the Underworld; and when the target of her Charm is a ghost. It also applies without cost in times of true desperation, when failure means death or ruin, and when a Princess intends to act on behalf of the Queen of Tears or her subjects, or in the interests of her own Nation and its members.
The Invocation does not resonate with those who will not do everything for those they protect, who show any moral compunctions in the deeds needed for survival. If a Princess' situation is such that her present goal can be reached at the least cost to herself and her Nation by committing a sin against Belief, and she chooses another course of action, she cannot use Lacrima for the rest of the scene, and for a further number of scenes equal to the difference of her current Belief and the level of the sin.
Favored by Storms
Tempesta applies at no cost when a Princess has taken enough bashing damage to suffer wound penalties, or any amount of lethal or aggravated damage; and in the midst of violent storms, earthquakes, explosions or other widespread devastation. It also applies without cost when a Princess is fighting servants of the Darkness or agents of the Queen of Tears.
Those who would use Tempesta must be merciless and swift, striking without hesitation and never showing fear. Displays of mercy to those who have wronged the Princess or those she protects or loves, or retreating from battle (pulling back to carry out an ambush is acceptable, fleeing is not), render this Invocation inapplicable until the sun next rises. If the target spared is a servant of the Queen of Tears or the Darkness, the Invocation cannot be used until the Princess's final health box is filled with damage, for their flesh cannot channel these powers until the weakness has been forced out through pain. A Princess may injure herself to regain use of Tempesta; in fact, such penance is expected and encouraged among Furies.
Favoured by Mirrors
Specchio applies at no cost when the target of a Princess' Charm is the Princess herself. It also applies at no cost when the Princess intends to set an example, to convert others to her cause, to impress others, when failure would lead to humiliation or embarrassment, to focus attention on herself or to prove how unique and special she is.
Those who would use Specchio are expected to be the shining light for the world, the Invocation does not resonate with Princesses who show humility, who deny or attempt to downplay their own accomplishments, or let others shine brighter. Even on a simple disagreement the Princess must prove herself correct, or at least convince the crowd, or else she loses access to this Invocation until the next day. However, in this time period, Specchio may still be used, if-and-only-if it is used on an individual who was responsible for the loss of the Invocation, although the cost of the Invocation is never waived. If this act of pettiness succeeds, full access is granted again.
Sidebar: Dancing in the Twilight Edit
One of the dirtier secrets of the Radiant is the sheer number of Nobles who, at one point in their life or another, dabble in the Invocations of the Twilight Queens. Dabbling in this case can be anything up to buying two or three dots in the Invocation, and usually only in one of them; more requires commitment to the ideals of the Queen which is largely incompatible with remaining a member of the Radiant (for one, one's own Queen will tend to object). And, in truth, it tends to be not entirely deliberately. The flaws in the Twilight Queens are ones which are within the hearts of man as a whole, and so most of the Enlightened have felt the same urges at some point in their life. Note that, however, such dabblers still consider themselves part of the Radiant, and, in the case of those who feel affinity for the Queen of Mirrors, see no contradiction at all in what they do. They still oppose the Darkness, and will fight against the loyalists of the Twilight Queens. One of the greatest topic of debate in the multiple, disparate groups of the Enlightened is how to respond to people who use Twilight Invocations, and whether or not they're doing anything wrong.
The Invocation of Lacrima, tool of the Last Empress, the Queen of Tears, is an object of fear and mistrust to the vast majority of the Radiant. It is apparently evil, in a way that neither Specchio nor Tempesta are, because of its links to Darkness, and to many, it is irrevocably tainted by the fact that it has the Charms used to drain Light from the world linked to it. But, nevertheless, there are those Princesses who learn it, and who do not follow the Queen of Tears. One of the fundamental things about Lacrima is that it can always be used to protect your own Nation, and to a Princess who wants to do exactly that, the expediency of methods means that Lacrima can look tempting. When a friend died because you insulted someone and so Legno was sealed off, the universal applicability of Lacrima for your Nation starts to look very tempting. The dabblers are typically more experienced, and more able to justify to themselves the moral compromises involved, in part because although there are Lacrima Charms which are Belief sins, for dabblers they tend to only have access to the ones which are sins against very high Belief, and so there are less of an objection. Moreover, there exists a notable sub-faction of the followers of the Queen of Diamonds who specifically learn Lacrima for its use in studying the dead and the Underworld, and, aggravatingly to some others, the Queen has said things which seem to support them. Such dabbers often have a strict moral code restricting their use of the Invocations to only using it to deal with the dead - never on mortals, and they point to the gains in knowledge that they have provided to the Radiant; their detractors point out that once the power is there, it can be hard to resist.
The Invocation of Tempesta, tool of the Seraphic General, the Queen of Storms is for most of those who dabble in it, purely a weapon. It is something that is learned as a tool against the Darkness, and it is used for that role. It does not (generally speaking) heal or right wrongs, but it does eliminate the followers of the Darkness and of Alhambra. In Glasgow, in the mid-90s, almost an entire generation of Radiant Princesses knew at least the basics of Tempesta. So hard-pressed were they by the Darkness and a major, well-organised Alhambran Outpost that it became unofficial policy for elder Enlightened to guide each newcomer towards it, because the universal applicability of the Invocation in such circumstances was too much of a boom. That large numbers of Nobles in the city were driven towards extremism was viewed as an acceptable price, even if by the end, and the arson of the Alhambran Outpost, there were Enlightened just as callous as the worst of Storms, still officially among the Radiant. For those Princesses in the know, too, Tempesta can also be sometimes the most moral of the Twilight Invocations, because the innate costs to it, the damage it does to the user, is known, and only affects the self. The common consensus is that it is dangerous, and a sign that a Noble is starting to spiral into extremism, but whether the use of it should be enough to ostracise one of the Radiant is a lot more contentious, especially since in areas where it is done, there are frequently not the Enlightened to spare.
The Invocation of Specchio, tool of the Crown's Custodian, the Queen of Mirrors, however, is the most subtle and insidious of the Twilight Queens, and the influence it is. In part, it is because of the lack of an overall enemy that the Invocation is linked to; while both the Ravens and the Furies provide a highly visible "there but for the grace of the Light I go" example which other dabblers can keep away from, the egotism and self-righteousness implicitly promoted by the Queen of Mirrors, and the lack of a solid adversary is hard to fight against, especially since many Princesses have tendencies in that direction naturally. Dabblers can slip into following the Queen of Mirrors much more easily, especially since the Queen does not demand fidelity, which means that some elder Radiant are much more harsh in opposing its use. There are those who argue that, unlike Tempesta and Lacrima, use of this Invocation makes you a de facto follower of Mirror's agenda. And on the other hand, there are those who count the Queen of Mirrors as among the Radiant Queens, despite the objections of the other five. It is so easy to learn, too; all one needs for it is self-belief in ones own cause, and a spark of the brilliance needed to reshape the world.
And neither are rare among the Enlightened.