[Lonestar]

Play a lot of monk, definitely a over-tuned skill. For very little investment you can do some huge damage (My build for the purpose averages 322 damage to a prinny with it without any buffs)

Setting Sun is also surprisingly strong, though I doubt anyone will agree there.

Setting Sun is strong, but not strong enough that I believe it would be deserving of a nerf. It costs 15 Ki for maximum range, plus on top of being 6M if you wish to activate it early. Can be avoided fairly easy unless the caster has some sort of movement displacement to place them back there, also the fact you can't activate it in the same turn you casted it. Doesn't help that Fire is also a very commonly resisted element compared to Terra Strike's Earth.

It can be done to deal some funky settings such as Grandupper into Setting Sun when they come back, though that'd require you being faster to make it work better.