Hello,
this is just for fun, similar to what was reported by IM Levy Rozman (GothamChess) in this series (the playlist is numbered backward, so the first video from the playlist is #7 and the final tournament game is #1).

At some point(s) the AI "forgets" about the actual position and raises alive a formerly removed piece, or plays some illegal move.
And yes, to proceed further with the game, the illegal position is enforced.
Sort of no-rule chess played one-sided (the AI) whilst the chess engine is obviously stronger but self-constrained to legal play.
Absurd, yet fun!
MfG
Tibono