If I conquer 2 battlefields on my turn, then my opponent charms my unit to conquer a 3rd battlefield on their turn, do I win the game?

Ruling: You cannot win this way. To win by conquering all 3 battlefields, you must score all of them during the same turn. Since you passed your turn, it is no longer the same turn where you scored the other 2 battlefields.

Nuances:

• You CAN win on an opponent's turn, but only if a single unit moves to all 3 battlefields and wins all 3 showdowns in one turn (such as being charmed multiple times in sequence)
• Special card mechanisms like Yasuo/Trynd may also allow winning outside your turn
• When your unit conquers a battlefield on an opponent's turn (but doesn't win the game), you still draw a card