Rolling in the Deep

Question: Are you required to spend Legend to resist social powers if you are in Virtue Extremity or Riastrad?

Well... I'm slightly confused about the spending Legend portion of your question, because normal resistance rolls don't involve spending anything; they use a power, you roll, you see who got higher. But maybe you're referring to the resistance knacks (Crazy Like a Fox, Disorienting Countenance, Parapet of the Mind), which do have a Legend cost associated?

Resistance rolls work exactly the same as they normally would when you're in Virtue Extremity; if someone tries to use their magical mojo on you, you automatically roll Willpower + Integrity + Legend and need to pay for your knacks if you want to try to apply them to the situation. The Virtue Extremity itself doesn't afford you any special extra resistances or anything, so it's totally possible for people to force you around in various ways while you're under its effects. That doesn't mean that they can shut off or circumvent the Extremity, however (only Mirror of Lunacy can do that), only that they can use the knacks while you're freaking out. That means that you will still be in Virtue Extremity if someone Overt Orders you to do something; you'll likely immediately go back to whatever you were doing as soon as its effects end or spaz out in an even more spectacular manner as soon as you can, but the power did work as normal.

Much to the deeply detrimental amusement of us Storytellers, that means that well-meaning bandmates can often trigger extra Virtue Extremities on top of you by trying to prevent you from acting on your current one. To use a real-world example, if Eztli and Sowiljr encounter a giant monster that he doesn't want to fight because they're in a hurry to go elsewhere, he might order her to leave it alone, forcing both of them to roll their Courage. Sowiljr fails the roll and is good to go - he has more important things to do than punch sea serpents all day! - but Eztli succeeds and hits the Berserker Fury Extremity, hurling herself at the monster in spite of his protests. If Sowiljr then tries to get in her way to stop her and gets a bone-shattering shot to the face, the fact that Eztli is already in one Virtue Extremity won't prevent her other Virtues from rioting over this misbehavior, so now she also has to roll her Conviction and Duty. If she succeeds on those rolls, too, she'll go into Morbid Self-Sacrifice Extremity as soon as her Berserker Fury is over, and then Fanatic Zeal immediately thereafter. We usually call this being stuck in "rolling Extremity", where the PC immediately rolls over from one kind of insanity into another as they process all the horrible shit they've dealt with lately. (The exception to this is the Extremity you're already in; if you went into Expression Extremity this scene because a painting was destroyed, and then someone also burns a bunch of priceless drawings in your immediate vicinity, you won't have to roll your Expression again. You're already busy freaking out about that.)

Rolling Extremity, as you might imagine, sucks a lot and is very dangerous to the continued survival and sanity of both the PC having the problem and everyone around them. It doesn't happen very often, and although a character can do it to himself, it's more often the result of his bandmates trying to pull off some damage control that misfires. That doesn't mean you can't try to perform damage control when you have an Extremitying friend on your hands, of course - just that, like all other times in the games, you should be aware of your bandmates' Virtues and the fact that you might cause a meltdown if you blatantly oppose them too much. And give them Willpower if you can.

By the way, since we're talking about social powers and Virtue Extremity, it's also worthwhile to point out that we make sure that no social knack gets to just shut down an Extremity and render it useless. For example, if in the above scenario Sowiljr responds to getting his face broken by using Compelling Presence to stop Eztli in her tracks, that'll work just fine, but he can't just sit around for the rest of the scene and expect her to be normal again when she snaps out of it. That's a pretty obvious bending of the knack's intent, and since Eztli is effectively in a sort of timestop, where she can't do or see or think anything but Sowiljr, she'll come out of the Compelling Presence with exactly as much Virtue Extremity left to get through as she had when she went in. Thanks to the memory-erasing effects of the knacks, she may not even remember why she's so upset, but she still will be. Virtue Extremities are a big deal and a serious moment of crisis for a character, and anyone who doesn't have direct control over insanity (i.e., people with Moon high enough) is helpless to stop it.

Riastrad has specific clauses involved in its writeup, so it's a special case that doesn't always follow the rules of other Virtue Extremities. Because it drops your positive Appearance to zero, your Bedazzling Image and Disorienting Countenance may be totally useless to you now, but on the other hand if you have negative Appearance you'll gain a dot, so you may be better than ever before. Where normal Virtue Extremities can't be talked down by unpowered use of plain old stats, Riastrad has a clause that allows others to make an extended Charisma + Presence roll to try to bring you out of it. Riastrad tends to hemorrhage Legend like nobody's business, but if you have some left over, there's no reason you can't spend it on resistance knacks if you want to. (Unless you put Army of One on your Riastrad, in which case knack usage is off-limits to you as it is to everyone with that boon active.)

Basically, there's no difference in the mechanics of resisting powers than there always is; the only difference is that you're batshit crazy at the moment, so you might respond to those powers differently or react after they've been triggered more strongly than at other times. That's up to individual players' roleplaying and the Storyteller's call, though, so, as with any time Scions have lost their minds, anything could happen.