[quote=@Vlad Tepes]
<Snipped quote by Sanity43217>

Ah, ok.  That reminds me of Shanoa and her glyph ability from [url=https://en.wikipedia.org/wiki/Castlevania:_Order_of_Ecclesia]Order of Ecclesia[/url].  I would assume this power has some drawbacks though, like say absorbing too many essences at once could harm them severely or outright kill them, or over time, their bodies would begin to deteriorate because of consuming the souls of beasts and spirits alike?  I leave this up to you, of course, but I think there needs to be a sort of limit as to what kind of souls and how many he can consume. General rule of thumb is if it’s sentient, the more powerful it is, the louder it is. 

"Hey guys, we just killed this huge Chimera and now I'm going to eat its soul!"

"I don't think that-"

*SHLORP!*  *Swells up like Violet from Willy Wonka*  "Uh...I think I fucked up."  *Gory explosion*

"Holy fuckballs!  Well...there goes our shaman."

[@Zeroth]

Oh Christ, not again! *facepalm*
[img]https://media.giphy.com/media/tJMVcTfzDdL1pOGxlk/giphy.gif[/img]
[i]THE GENTLEMAN IN THE SILLY HELMET HAS BEEN THROWN OUT[/i]
[/quote]

Can’t say I’ve played it. 
As far as limitations go, the acquiring of powers would be heavily ritualised, which would lead to three key limits as to where he gets his powers from. 
1. The ritual itself and specialised ingredients. Depending on the creature, spirit or being there could be very specialised ingredients that they might not have access to. 
2. The time it takes to do the ritual. Just throw weaker enemies to disrupt the ritual. The stronger the thing he is binding, the longer it will take. 
3. The ‘volume’ of the thing. Because he is taking in their full essence, it’s not so much the physical size, but mental energy. He has learned to live with the background hum of his ancestors, but taking in more sentient things might get a little crowded in his head. So no stealing Liches because they tend to make bad head mates.