Implemented on a magic item: I started working on Menace because I was designing Chitinous Cloak for my next Zendikar Equipment post, so heres an example of my Menace rule used on that item (also being a little preview for the next equipment post!): Chitinous Cloak Wondrous Item - Uncommon You gain a +1 bonus to AC
Falthis, Shadowcat Familiar Falthis, Shadowcat Familiar gives your commander plenty of claws
Sure, your opponent gets too as well, but if youre dropping a creature with an exceptionally powerful enter the battlefield trigger, like Atraxa, Grand Unifier, a creature that is practically unstoppable like Emrakul, the Aeons Torn, or an enchantment that gives you free rein to do whatever you like Omniscience, you basically guaranteed a win
Which, as it happens, is a bunch of starter decks and some dumb-ass AI to play against, with a meticulous series of tutorials to follow