A planeswalker is a powerful character in the trading card game Magic: The Gathering. They possess the unique ability to travel between different worlds, known as planes, and harness magical energies. Each planeswalker has their own distinct abilities and spells, making them valuable allies in battles. In the game, players can summon planeswalkers to aid them during matches. These characters have loyalty points that can be increased or decreased based on their actions. Players must strategize to protect their planeswalkers while using their abilities to gain an advantage over opponents.