Theo is fantastic, actually. His character is proof that pure confidence is extremely intimidating. Aside from Diamondback, he's completely unafraid of anyone who steps to him. He's always got that calm, confident grin.
The new home of Welcome to Planet Bob:
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Having not seen Sons of Anarchy, I thought the Shades character was great, probably my favorite of the three main villains.
Ali as Cottonmouth was cool. I wanted to see what he would with it after watching him in House of Cards. My only problem was that little laugh he always did when he thought he was being clever or something.

32, white, male, straight.

Ali is a good actor. Rossi did okay, I didn't like him in Sons of Anarchy at all - he always seemed out of place there.
I never saved anything for the swim back.

i would describe their casting as a stroke of pure genius.
however, the writers let cottonmouth's character down.

For the most part I think the casting was pretty good otherthan Theo Rossi

I love Ali, felt he was ok in this. I don't know the source material to know how imposing or not Cottonmouth was suppose to be. He didn't have the presence that D'onofrio has as Kingpin.
Theo, the problem is I hated him as Juice in Sons. Rather, I hated the character. So weak and sniveling compared with the rest of the club. Seeing him trying to be cool here came off as wonky and forced initially, like I always was waiting for him to unleash some eye beams like Cyclops or something.
I think overall, the villains felt weak in this, I don't blame Theo or Mahershala.

That's personal beef, I thought they both did really well.

I think Theo did great tho.