(could definitely expand this out to have some sort of rotating monster list with collective punishments if you don’t do enough damage to it. but keeping stuff simple unless people express a desire for more)

Should this have a trait? If so, Belligerent, Benevolent, or Reclusive, since it’s really self-harm?

The reason I’m asking is that it would be simple enough to let the Charm build up to 5 on this, then every Wizard could cast it for “free” in the same Duel and get the achievement. Even at 3 Charm it might be worth it for two Wizards to collude and both get the achievement.

With a trait thrown in, that could make it a little more difficult to collude since different Wizards will have different needs and penalties according to the traits they’ve accumulated so far.

I think that’s fine. It adds to some mind games. Do you strike like you suggested when its 3 charm? Or maybe you just throw 1 star at it when its 3 charm thinking others will still go for it and you’ll win? So maybe you and your friend go for it at 2 stars so no one else can ride your coattails…

I don’t really find this sufficiently interesting in terms of mechanics compared to everything else.

For above reasons. Also “The kaiju spell” doesn’t exist, so the achievement wouldn’t be possible to achieve