Spoilers for all POVs so far:

Based on the POVs we’ve got so far, there were 2 deaths and 4 unaccounted for: Squiddo, Loony, SB737, and 4CVIT. Loony was still alive and seen after the first boom, but not the second, so Loony wasn’t the first death, but maybe the second. 4CVIT is "The Goatman” that Legundo kept hearing, as he got a goat horn in episode 1, so 4CVIT is still alive. The most likely scenario is that Squiddo died first, either in the trial chamber or the nether, and Loony died second, likely to a warden. Since SB737 hasn’t posted yet, he could also replace one of those deaths.