Vesperlark loop
Playing on Android, I cast a wrath of God into two vesperlarks on board, nothing in graveyard to get back. Opponent gives one vesperlark perpetual -1/-2, which starts the loop only on itself with no life gain or loss in play. I think that opponent should just time out his turn doing a nothing infinite-loop, but the match ends and declares a draw. Where is the draw? His turn should time out, my spell should resolve, ultimately leaving both larks in the gy. I feel I was cheated out of a win in an event match, which will result in lower placement and prizes, if someone could get back to me about this I would appreciate it, thanks!

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mobpsycho200#22729 commented
I experienced the same bug playing Jumpstart Historic Horizons on two occasions.
I had 1 vesperlark on the board and no creatures in the graveyard.
Opponent plays a spell targeting verperlark that gave it perpetual -1/-2, so vesperlark is sent to graveyard, triggering its ability. Because of the perpetual -1 power, verperlark's power in the graveyard is now 1, so it automatically targets itself.
Upon returning to the board, its toughness is -1 because of the perpetual -2 toughness caused by opponents spell. It is send back to the graveyard, triggering its ability again in a loop that can't be broken.