>>15925085Mega Blastoise is pretty great, but one might argue that a Clawitzer with an item is worth more. Same with Mega Heracross and a Cloyster with an item.
The main issue with Mega Blastoise is that there are better Pokemon that do more with being Mega and if you get a Speed Boost Scolipede/Blaziken to Baton Pass into a Clawitzer with a good item, then you're good to go. At least with Heracross/Cloyster they have different typings.
I have fondness for Mega Blastoise since it was the first Mega I finally tried out (didn't touch them during the main game but I liked Clawitzer so much I figured why not) and it looks awesome, but since you only get one, you're probably better off rolling something else.
No idea about Hera since I got X. Still hoping to come across one of the "I'm restarting my game" threads early enough to get that or Aggronite.