Homebrew
Brave. The gladiator has advantage on saving throws against being frightened.
Multiattack. The gladiator makes three Shortsword attacks. It can replace one attack with a use of Shield Bash.
Spear. Melee Attack Roll: +7, reach 5 ft., one target. Hit: 11 (2d6 + 4) Piercing damage.
Shield Bash. Strength Saving Throw: DC 15, one creature within 5 feet that the gladiator can see. Failure: 9 (2d4 + 4) Bludgeoning damage. If the target is a Medium or smaller creature, it has the Prone condition.
Retaliatory Strike. Trigger: The gladiator is hit by a melee attack roll while holding a shortsword. Response: The gladiator makes a Shortsword attack against the creature that triggered the reaction. If the attack hits, it does an additional 3 (1d6) damage.
Any Climate; Any Terrain