While outside the scope of this list, let me just go ahead and assure you that Contract from Below is a clear first place in the entire game, if you happen to be playing for ante
Mentor is an ability that triggers when it attacks, and it allows you to put a +1/+1 counter on another attacking Creature that has less power than it
Im not convinced Genku will helm a lot of decks, though
Legality depends on the tournament format -- Goblin Coward Parade can be legal in some formats and banned or restricted in others
Prices were taken from TCGplayer on Thursday, Sept
However, Ashcoat will eventually need evasion in the form of fear, menace, or unblockability to survive such attacks (he does not gain the boost himself)