Mitch, Financial Judoka

First Strike, deathtouch
At the beginning of each upkeep, put investment counter on Mitch and a kuzushi counter
on a creature.
{t}: fights target creature with a kuzushi counter
on it, it gets -5/-5 until end of turn.
{t}: Add {x} to your mana pool where
{x}= (1+r)^(n) r= 10% and n= investment counters
​