MCU: Kaecilius runs the gauntlet

Round 1: Captain America
Round 2: Killmonger
Round 3: Fandral
Round 4: Hogun
Round 5: Star-Lord
Round 6: Loki
Round 7: Ronan
Round 8: Valkyrie

• Standard gear
• Kaecilius gets healed after each round
• Takes place in the New York Sanctum

Probably 3

Dark Dimension amped? no restriction?

he clears

He can simply take the fight to the mirror dimension and leave his opponents there. Nobody here has a counter to that.

That also means he can never use the mirror dimension again in the next fight or they're there...and then that fight continues so it's not as effective a BFR when you need to access it.