Dude stick to spawn comics. Ikaris is to damn powerful for starfox even though I like him he stands no chance in hell, with out the prime eternal powers Ikaris still kick the sh** out of starfox.
Titanian Eternals will always be inferior raw powerwise since they can't synthesize cosmic power within them with the exception of Alars and Thanos. I don't know though if titanian eternals have some sort of compensation for what they lack but specifically on this fight, Ikaris should have the clear upperhand specially after becoming an eternal prime.