Because this whole line is based around symbiosis, i had some concept in my head regarding their mega evolution. In order to megaevolve Slowbro/Slowking, you need to have both of them in your party and a Slowbronite or a Slowkinite. When megaevolving, the two of them will fuse together, and the Mega evolution will be called Mega Slowbro or Mega Slowking depending on which mega stone you used. That's why their mega evolution has elements of both Slowbro and Slowking.
Mega Slowbro and Mega Slowking look the same, they just have different stats.
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