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Sylar from Heroes? He doesn't eat people, he just kind of takes a close look at their brain to understand their ability.

Here they are in order :3

Re:Monster - this is a guess, I haven't read it in like 2/3 years.

That Time I Got Reincarnated as a Slime

BOFURI: I Don't Want to Get Hurt, so I'll Max Out My Defense

Arifureta: From Commonplace to World's Strongest

Kirby

Attack on Titan

Finally the spider: So I’m a Spider, So What?

Some similar ones too, just in case you're looking for this genre:

I Grow Stronger by Eating

Berserk of Gluttony

Guy with the white hair and guns is the MC on Arifureta: From Commonplace to World's Strongest

And the spider is from So I'm a Spider, So What? (I really enjoyed this anime)

Partial list

BOFURI: I Don't Want to Get Hurt, so I'll Max Out My Defense

That Time I Got Reincarnated as a Slime

Attack on Titan

I recognize Kirby, and that's about it.

I think the dude on the far left is from Re:Monster, maybe?

Absolutely.