Considering how much Mewtwo is hyped up for how powerful it is, at a glance, the Mewtwo card in the base set isn't that powerful
These are actually both pretty straightforward, and will likely pass any reasonable Rule 0 conversation
Teach (Black, control) and Shanks (Red, board suppression)
Scrying multiple times can often be better than a draw effect when you're playing highly synergistic cards like boros convoke does
This evasive keyword will help your creatures break through your opponent's blockers and go for the throat
You gotta talk about your win conditions yes, you should be open with your decks information, and not cagey, because if youre not, it just creates mismatched expectations, and the potential for people to not trust you in the future