Critical damage

I believe yasuo's crit reduction is additive so his base crit damage is 190% but with an IE that makes it 240% so any crit damage runes you use will just add onto that 190% damage.

Jhin's crit damage reduction, however, is multiplicative. Not sure on the exact amount, but it means that your crit damage runs will be less effective on Jhin. but really crit damage runes are kinda dumb for the most part and generally not very efficient.