Suppose I see a 20% chance that 20% of the multiverse is covered by 100 deterministic universes such that each
Then they could see what everyone does. I, having mastered this cosmos, could simulate them and see what I can prove about how they will use their hypercomputer. If they have something to trade with those like me, they might deliberately write an AI to control their hypercomputer, in order to make it easy for those like me to prove things. Suppose one alien race evolved to value diplomatic rituals and would like other universes to instantiate an ambassador of their race. Suppose "the portion of the multiverse that instantiates infinite happy humans" accounts for 20% of my utility function. Then I could construct an embassy for them so they will spin off an "infinite happy humans" thread, increasing my utility by ~1/100*0.2*0.2*0.2.