To be clear, you cannot die while playing as Godzilla--you'll always turn back into a normal player at the end of it, no matter what. From there, you'll play the rest of the match out as usual. You don't, by the way, get any rewards for having been Godzilla in a match, aside from the happy memories.

Become the legendary monster! Godzilla will be available from this Friday, January 17 in Fortnite with the v33.20 update