Laquari x2-3, Bestiary x1-2, Murmillo x1, Sagittarii x1, Retiari x1, Secutor x1, Test Tiger x1, War Chariot x1. Fill the rest of the 10ish cards with whatever traps/spells that will help your monsters survive a battle or Cosmic Cyclones. Keep in mind that Gladiator Beasts are too slow of a deck to be competitive, but it should at least be playable for fun duels.
Thanks for the input guys. Having just 1 Gyzarus is going to be an issue. But we could get a second on the next Dream UR, hopefully. Is 3 tigers necessary? Unexpected Dai Gyzarus turbo looks more promising than the tigers.