No, he is not eating them. Since Ridley was killed during Super Mertoid, we, Ridley cult, decided to use deconfirmed characters` blood to ressurect our lord by mixing that blood with his ashes and parts prossessed by us.
I prefer more active and satisfying Final Smashes like Aura Storm, Great Aether (my favourite one, it is so awesome that only Ridley and Grimlock are more awesome than that and nothing else) and Galaxia Darkness. And maybe Mega Man`s final smash. So, i would prefer it to be either something like Great Aether or Aura Storm, but with a little bit of a special Ridley touch. So, instead of Aura-Kame-kame-ha-something, it is his plasma beam charged up to maximum power...i used that idea already and it may not look very awesome in the way i made it (mostly because it is in 2D and not even 2.5D), but it still looks fine...i guess...