At the beginning of each player's upkeep, that player creates a 5/1 red Elemental creature token named Lightning Rager
This is an excellent play later in the game, particularly after your opponent attempts to win back control of the duel with an Exciton play
Whether used in control, tempo, aggro, token, or midrange, whether in maindecks or sideboards, Avacyn put in work
If you didnt already have a card to counter it in your very next turn, it was over
Bonus, though, is that the Lisa Marie Secret Lair version of Crested Sunmare is a great spec if people decide to build Thurid decks
This is fine playing against him as it is only on his turn so taking him out shouldnt be a worry