Maths isn't my strength, but I'll try to explain.
Super Skrull copies all of the enemy cards' ongiong effects. The other player had Onslaught, so my card copied that. Then I put down my own Onslaught card, which I think was a copy gained from Morph or Mirage, so it wasn't even part of my deck.
So two Onslaughts doubling each other's effect, and Onslaught's Citadel doubling both of their effects, which doubled their effects on each other again. I think this would mean both cards were increasing effects by 16 times?
Then Iron Man doubled the score of the other cards. Except that was doubled 16 times, then 16 times again, then doubled by the Location.
Then Devil Dinosaur got +2 power for every card in my hand. But that +2 was multiplied 16 times, then 16 times again, then doubled, then this final score increased by however many times Iron Man now doubled the score.
I'll never manage to do it again, but I'm happy it happened once. #MarvelSnap can be wild.