I want to give mid-to-high level monks an ability similar to kaio-ken from Dragon Ball Z, but I'm not quite sure how I want to implement it. I was thinking of having it provide large physical ability score boosts and temporary ki, but when it ends you take Constitution damage based on how long you maintained it.
Any suggestions? I run some very high power campaigns, so go nuts.
Spend 2 ki points as a swift action to gain a +4 enhancement bonus to Strength, Constitution, or Dexterity for 1 minute.
It works out pretty well because several qinggong powers cost 2 ki points to mimic the effects of a 2nd level spell. It'll still be useful at higher levels since PCs rarely get magic belts that grant an enhancement bonus to more than one physical score.
Maybe you could do something like a mini-rage ability that gives you a bonus to strength by spending Ki Points, but you take non-lethal damage equal to your level similar to the Kineticist Burn mechanic.
Make it like Chakra, in that each stage you go through has to be opened and maintained (with the threat of damage or losing all the ki you spent to open all previous stages).
Replace normal Chakra bonuses with +X to attack and damage. With 2 Chakra opened, +X to Reflex saves and STR/DEX skill checks too. 3 open +X to AC. 4 open +X*2 temporary HP, recharging every time you open a new chakra but only once per minute. Etc.
Well in DBZ, how kaio ken works, is that it gives a temp multiplier to the user but drains their ki, or life force. You already have the advantage of monks having a ki class feature. Maybe convert it into a "X ki = dmg multiplier / level" or something like that. You can choose what the X is and you can make the dmg multiplier scale as you see fit.
Thanks for the suggestions. I'll play around with them and see what I get.