Zoruagible
Lover of underrated characters
I think I will be picking Treecko because my brother wants Mudkip and I already used Torchic in Y. If Dawn Stones are available, I will definitely use a Gallade with its Mega Stone. If not, my mega will probably be Salamence or Altaria.
Dawn stones will definitely be available. Why would they make a new Mega for a Pokemon who evolves from a stone if that stone isn't obtainable.
The question is where will the stone be obtained.