Mk. So... He could also have... Lemme see.

If he has goons, maybe he could have some power tied to their loyalty or souls, something like that. (A double-edged blade)

He could also lose his Divine Slayer status by falling from grace? Maybe?

@Yoruharu he was used to being powerful and near unkillable, and he’s had some physical and psychological issues caused by different Physiologies in the past, but while fighting this villain I’ve been setting up since the 2nd or 3rd year of role playing (behind the scenes) he is going to die but is saved by this being who is supposedly a god (just this power hungry being trying to use him to get out of this prison-like realm). He goes in to use this being as an inspiration to create this drug that allows him to access all of his powers at a bot of a boost (not the boost mentioned in the post) and once seeing how powerful he is, he decides that his friends are gonna try and stop him so he tries to send other powered beings to hunt them. Fast forward 10 years and after a lot of fighting and terrorist attack like things on his company and his city, they end up killing him. In the 10 years he’s found a way to use his different Physiologies to live after death. Basically since he’s a demon as well, he should go to both he double hockey sticks (just had to make the reference) and the speedforce, so he ends up going to this dimension in between them as this hybrid, no longer looking fully human anymore, more like a mixture of a demonic monster, and a speedforce being (think black flash), so since he’s not trapped in either of those dimensions he’s able to escape and hunt his friends who killed him.

That's a lot of points you could tackle and try to find the weak spots, then put them into the campaign dynamically. Sound like a nice ”Final Boss” BBEG.

@Radmushroom when I first introduced him about 4 years ago (son of my original character who my profile is named after) he was a speedster and that’s about it. Over the last 4 years I’ve been evolving him bit by bit (if I’m honest with myself I’ve been planning this for a while) and it just kinda feels like there’s no where else to go with him, so this is kinda like a send off

@Hestarne Hum. that final boss thing was kinda what I was going for

Edit: that divine slayer thing would probably happen but I just don’t see how that’d beat him

If you're doing DnD (maybe using another system, sorry for just assuming) with homebrew, I'm not sure. But by DnD 9th level spell standards, this guy would only mean death by his God Physiology and Speedforce. Don't see him as that big of a threat as a boss on his own unles the campaign has some roguelike permadeath shenanigans.

@Herostorm MC

Maybe the official gods from the roleplaying system you're using demote him for not being worthy. xD

@Hestarne Hum. not really going for DND, but I’ll probably end up using it for spells. With his current state it’ll probably be a mixture of a Kakuja, a demon, and that pseudo-speedforce being

Meh, who knows. If you're DMing and have a hang in your land, you can probably come up with some pretty nice stuff for both the heroes and 'Da BBEG. The development is pretty nice (4 years is quite some dedication) and he has quite a pedestal, but just remember this when adding abilities and strengths:

”The taller they are, the harder they fall”.

Btw, it's past midnight at my country, so Imma go get some stamina refills rn. Wish you good luck at your campaign till its very ending.

@Hestarne Hum. well there’s definitely been times when we’ve taken some decent breaks due to burn out or boredom, but it’s not really D&D, just an over-text roleplay. Have a good rest lol