Axiological realism holds that there really is an objective moral law. Arguably, this suggests the possibility of being morally perfect. Could axiological realism support the ontological argument?
1. Possibly, a morally perfect entity exists. (Premise)
2. Necessarily, it is better for a morally perfect entity to exist in all possible worlds than not. (Premise)
3. Necessarily, whatever is better in a possible world is possible in that world. (Premise)
4. Possibly, a morally perfect entity exists in all possible worlds. (Implied by 2 and 3)
5. Therefore, a morally perfect entity exists. (From 4 and S5)
I'm not sure if this is a sound argument. I'm just thinking out loud, as it were.