Mega Salemence is such a bad design, I mean ugh. Mega Altaria is pretty predictable, but it's a nice enough design anyway.
Mega Lopunny though! Honestly its weird proportions have always seemed a strange design choice, and I'm not too sure about the mega's design, but I'm really excited about it competitively. Scrappy means it gets perfect coverage with its STABs, letting it abuse its extensive movepool in its last two slots. Stuff like Encore, Baton Pass, Heal Bell, Healing Wish, Quick Attack, even Scrappy Fake Out for doubles. Not to mention its defenses aren't awful, a 15 boost to each will leave it with 65/99/111, which isn't bad at all, and it still has 70 points to pour into attack and speed (although its speed only needs like, a 15 boost to be really quick).
And with this it's immune to ghost and resists dark, the premier attacking types in the current meta. Even if it doesn't make it OU, I'll have a lot of fun with it in UU if GF don't screw it up.