Temur's challenge

Start with this card in the challenge zone. At beginning of your upkeep put an age counter on it an roll a dice:
1/2 - Put a 4/2 Creature token into battlefield
3/4 - Creatures into the challenge zone gains +X/+X and trample until the end of turn, being X the number of age counters on Temur's challenge.
4/6 - A creature you control fights another creature you control.