Arcann vs Darth Baras and Darth Thanaton

All-out fight, to the death, on neutral ground.

Who wins and why?

Arcann. It's not even close.

Thanaton oneshots him with sorcery.

Arcann. Ragdolling someone who defeated Baras/Thanaton doesn't reflect well on the duo. He should also be a far better duelist than them.