If the first ability resolves but the target opponent can't become the monarch (perhaps because they also had a Jared Carthalion enter the battlefield earlier in the turn), the current monarch stays the monarch, even if that player is you.
Jared Carthalion, True Heir
The game starts with no monarch. Once an effect makes one player the monarch, the game will have exactly one monarch from that point forward. As a player becomes the monarch, the current monarch (if any) ceases being the monarch.
If the triggered ability that causes the monarch to draw a card goes on the stack and a different player becomes the monarch before that ability resolves, the first player will still draw the card.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Lius Lasahido
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
