Chance for Glory by paying its mana cost, causing you to take an extra turn after this one and to lose the game at the beginning of that turn's end step.
Activate
Magar by paying ({1} magic symbol) ({B} magic symbol) ({R} magic symbol) , noting
Chance for Glory and putting it face down on the battlefield as a 3/3 creature.
Activate
Magar by paying ({1} magic symbol) ({B} magic symbol) ({R} magic symbol) , noting
Day's Undoing and putting it face down on the battlefield as a 3/3 creature.
During your next turn, deal combat damage to an opponent using the face down creatures that have
Chance for Glory and
Day's Undoing noted. The creatures trigger.
Resolve the first trigger, casting a copy of
Chance for Glory without paying its mana cost. Resolve the copy, causing you to take an extra turn after this one and to lose the game at the beginning of that turn's end step.
Resolve the second trigger, casting a copy of
Day's Undoing without paying its mana cost. Resolve the copy, causing you to end the turn. This will prevent the
Chance for Glory trigger from causing you to lose the game.