Need some FeedBack

Hello, People of Pokecommunity! I was thinking of an Idea for a ROM hack I was going to do. I was going to make an evolution for Eevee, where it kind of has Arceus DNA.
Should it's type be the type of gem it's holding?[who remembers the gems from gen 5?] Or should it just have protean?
I hope you guys reply!
-RattataDude

Well I mean the Gems were there in Gen Vi and VII as well just unobtainable by any legit means other than Normal Gem.... much to my chagrin, I might add :/
Silvally is already like an Arceus-lite and he's kinda lame. So my vote is the Protean option. Since that will make it a little more dynamic if you ask me.

Alternatively, I have a plan for an ability in my own hack where it's kinda like an inverse of 'Color Change'. So, instead of changing to the type that the 'mon is hit by, they become the type of the thing they hit instead. Kinda like stealing their essence/ life-force type of thing. Not sure if that's the theme you're after , but it could be something to consider