This makes him incredibly easy to build around, given the sheer number of +1/+1 counter support cards available in the Commander format
Why not just let it through
Then you would steal the scariest threat on the table or you could take your opponent's commander, if their deck relies on it heavily, effectively neutering them until they can remove it and recast the commander
Ruby has a theme of self-damage in Rise of the Floodborn and this Donald gives you a nice payoff for damaging him
Pros and Cons These are super doable challenges just for playing the game, because when I discovered this, I'd already gained enough life to complete the Claws of Bast challenge
Persuasive Interrogators If I can investigate, make five Clues and then play this, all I need is 10 mana to win the game. I think these Persuasive Interrogators have given you Stockholm Syndrome