There, you need to CHOOSE one of three. I chose the blue one, with a hero.
Hint!
Explore the map; there are some purple keymasters scattered around. And near Sanctuary, there's a portal blocked by a purple tower. Behind it are 110 Death Knights, 420 Mummies, and 1050 Zombies, and a GOOD artifact. Use it! This will make defeating Sanctuary twice as easy.
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