I'm not sure because to be omnipotent is to be powerful then all meaning there can only be one

And if the omnipotent being decide that there are two omnipotent being and then kill the second omnipotent being

Omnipotence is so complicated to be fully understand by us, it is my point of view

There can only be a single omnipotent being, the moment that one is stronger than the other or both possess the same power them neither of them is truly omnipotent.

Are you sure, Omnipotence can do anything and everything then why an omnipotent being cannot create an other omnipotent being and kill this omnipotent being?

Say that there can only one omnipotent being is say that an omnipotent being cannot create another omnipotent being different from him which is a limit of a limitless power

I don't see being kill by another as an indicator of inferiority, if I'm omnipotent I can decide to die, I can also decide that an ant could kill me, I can decide to be kill by an ant and to cannot stop that because I'm not constrained by a normal human logic, I can also decide that everybody reach Omnipotence

That logic is closer to Metapotence rather than Omnipotence, give it a look at the wiki.

Otherwise it does make sense that he could do it, but I cannot see the logic of creating another omnipotent being only to kill it.