The text says “when you gain 3 or more life this creature transforms”, however the transformation doesn’t happen until end of turn. I had a 6/6 lifelinker in slot 1 and lone rider was in slot 3, the transformation should have happened after the first creature attacked and before the second, but it didn’t happen until after combat.
Creature #1 was the Ascetic, #2 was an angel stack from LA, #3 was Lone Rider. They were all buffed with Starfield’s +5/+5. I believe Archive and a flipped StV and Settle were also out, along with maybe a treasure or 2. Greg had 1 or 2 creatures I don’t remember.