How to destroy portals in the Sanctum?

[drmarkandersen]

Since defeating the Sorcerors without destroying any of the portals in the Sanctum is considered an achievement, it stands to reason that there must actually be a way to destroy them. I can't for the life of me figure out what that might be, though. I've tried '>', and I've tried the Orb of Many Ways. I've tried 'attacking' the portals somehow, the way archmages have to attack the portals in the Abashed Expanse. Nothing that I've tried has worked. Hints?

[Faeryan]

Four portals, four Prides, four dropped items by pride leaders.

[drmarkandersen]

Thanks, that helps.

[Hommit]

Four portals, four Prides, four dropped items by pride leaders.

This works only while bosses still alive? Cause after they died using spheres does nothing.

[Jurriaan]

If you wait until the sorcerers are dead, it's too easy to be an achievement