Captain Rex Nebula + Brazen Dwarf + Assault Suit + Leonin Shikari

Captain Rex Nebula

Brazen Dwarf

Assault Suit

Leonin Shikari

How it works

1. At the beginning of combat, Captain Rex Nebula triggers, making Brazen Dwarf a Vehicle and giving it Crew 2 and "Whenever this Vehicle deals damage, roll a six-sided die and sacrifice this Vehicle if the result is equal to its mana value" until end of turn.
2. Activate Brazen Dwarf's Crew ability by tapping Captain Rex Nebula, making it a creature until end of turn.
3. Activate Assault Suit's equip ability by paying 3, attaching it to Brazen Dwarf.
4. Declare Brazen Dwarf as an attacker and deal combat damage with it.
5. Brazen Dwarf's ability from Captain Rex Nebula triggers, causing you to roll a six-sided die and fail to sacrifice Brazen Dawrf regardless of the result due to Assault Suit's ability.
6. Brazen Dwarf triggers from the die roll, dealing 1 damage to each opponent.
7. Repeat from step 5.