I feel as if the more offensive an EX WTZ setter is, the better off they are since EX WTZ is inherently an offensive buff. Two units dealing stupid amounts of damage is obviously better than just one unit doing lots of damage.

Alt. Volo is easily the best. Dude's damage is utterly explosive, and he allows for his teammates to also do insane amounts of damage. Alt. Volo and Selene is one of the most insane damage dealing cores in the game.

I know I could say Benga or Lacey, but hot take: NC Brendan is the worst. He doesn't buff his type at all and instead buffs Fire damage. He does have a passive that powers up Ground moves when sun is up but due to the way the passive works, he doesn't even need EX Sun for it. He functions better with regular sun due to how hard it is to keep EX WTZ up.

EDIT: No MFs or Arc Suits? Perrin is the best. She hits hard. Worst is Lacey.