This is a thought experiment and a continuation of how small can a cube really be. The 3 card Rock Lobster, Paper Tiger and Scissors Lizard combo wasn't exactly a challenge to design so instead I took the Rock Scissors Paper Lizard Spock game with 5 elements and dug through Scryfall until I found a combination that worked.

Each card should beat 2 of the other cards and lose to 2 of the other cards.

2 cards are dealt face down to each player, the fifth card is left face down as an unknown.

Players play their turn simultaneously as follows: Main Phase 1: Play one creature, go to combat and attack with that creature. Both creatures attack and block each other. The player with the surviving creature wins the round.

The cube name is a play on Rock SCIssors Paper LizArd Spock.