When the game starts, run right to Mewtwo. Otherwise your opponent has shadow ball and you get like 1/5 of your Limit meter... not a good trade. Look out for mini shadow ball traps too. As for Mewtwo's grabs, they can KO early but have bad range so you have more space to place an aerial on shield. I'd avoid platform stages because of Mewtwo's up smash, which they'll probably fish for around 90 and above. They'll also be fishing for (depending on the player) jab-grab, jab-disable, or even the infinite. The infinite starts with Nair, which you can get around quickly if you know it's coming. Mewtwo's Fair will break strings so be careful but also try to bait it out. Mewtwo's Dtilt is fast, long, and difficult to punish, so respect it and get away so you can space Mewtwo out. Also DI away from Mewtwo on Dthrow and Uthrow. It's a lot but I tried to put in everything I can.
Edit: I don't know nearly as much on Villager but from Villager's good Nair and shield grab I would think you should try to space your opponent around the end of your range so you're more difficult to punish but still able to land some hits. Alternatively camping and charging Limit could help
Anyone have experience on the Robin MU? I've yet to take a game off two different Robin mains as Cloud and as Mii Brawler