Ultimatism is, roughly, the view that an ultimate being exists. Complete ultimatism seems to be the least arbitrary version of ultimatism. According to complete ultimatism, a completely ultimate being exists. A completely ultimate being is a being that has all ultimate properties. But given complete ultimatism, there plausibly is a single perfect ultimate being:

1. A completely ultimate being exists. [complete ultimatism]
2. To be perfect is an ultimate property.
3. To be ontologically prior to all other beings is an ultimate property.
4. Therefore, a single perfect completely ultimate being exists. [conclusion, from 1-3]