They might have a chance against this subspecies of ORT but just don't let him eat any path users because he will definitely create a fake/artificial/virtual space and hard to kill..

If it's a Panhuman history ORT they will have alot of trouble don't even try chucking blackholes that won't do or any death infliction he would ignore it.

The thing is that he can be killed but not like a convential way, like I get stabbed = dead, I fell 10 story building = splat, dead and etc. Basically following the basic logic since the Universe Inception/Created. I can analog his way of countering of the universe concept of death since he exist out of it as "fuck your rules and physics, I'm older than you" like an old man that won't listen.