Mangadonf
Can we just call ophis a her and an idea for to get ophis on his side would be a room ( ever expanding ) made out of runes that ensure total silence
You don't have to dominate in order to gain and hold power. Learn and Earn power to keep himself safe and hidden, free to do what he wants, but not at the mercies / power of others. His freedom means nothing if he dies. Staying OP while being Low Key is possible and being only High profile when his life is in danger in order to save it. By the time others want to restrict his freedom, at least have the power to protect said freedom, which is not domination, but Ability of Self Defense and independent. It is the struggle, effort, and crafting to gain power for self Defense and independence. No need for being OP. Self sustenance, independence, and freedom all require the power to protect it.
Although Alex becomes a superdevil, he will continue to create objects because he is a lazy devil. Therefore! Making Alex a superdevil should not be a problem. The protagonist of One Punch Man is the strongest but the manga is not boring at all. Alex's laziness is the push to continue to invent new objects to the problems that he must face.