Character Card System

What does Mikhail's card do? I don't know if I want to delete my Thunder Breaker for it even though it seems to be the absolute best possible thing to do (all the benefits of KoCs but with an S card). Though i can only replace him in my deck considering I have the mercedes cooldown and the mechanic buff duration (or other way around or whatever). My deck so far is: Bucc, canonneer, Jett- then Mech, Merc, and Thunder Breaker. So if anything, I'd replace the Thunder breaker with the Mikhail depending on the buff. Decks are so hard to come up with -___-

My complaint with the 120 cygnus is that they still count as A rank cards and with how the card system is set up you really get a better bonus from an S-rank set than you get from any 3 character card set. If you're going to use a cygnus card you're probably better off using Mikhail regardless, assuming you have other level 120s for the card set.