That wouldn’t be realistic, they would win, but they’d have to work for it. On top of it all, Kalibak may not be one of the last two standing. Unless you can show me recently where either of the Eternals were punked. Thanos doesn’t really count either.
Gilgamesh is actually an anchor weighing the far superior Ikaris down. Thena or Sersi would have been better teammates by far. Having said that, all T2 needs is Orion. T2 stomps.
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..even the outer hells are indifferent matters for they bow only to potent and archaic Nodens.