UI very nearly did both because I thought we'd had to. That was the one riddle I'd solved (or so I think) quickly as well. :(

Anyway, here's the battle:

My Team:
Blastoise (Water, Final)
Alakazam (Psychic, Final)
Parasect (Bug/Grass, Final)
Hitmonchan (Fighting, Final)

Round 1:
Vs
Both are Final, but Blastoise has type advantages (Water vs Rock and Water Vs Ground). Blastoise wins!

Round 2:
Vs
Both are Final, but Alakazam has a type advantage (Psychic Vs Poison). Alakazam wins!

Round 3:
Vs
Both are Final, but Hitmonchan has a type advantage (Fighting Vs Normal). Hitmonchan wins!

Round 4:
Vs
Both are Final, but Parasect has a type advantage (Bug Vs Psychic). Parasect wins!