The tendrils of sentience reaching out from this orb are too much for even an experienced warlock like myself to withstand for long. I am reluctant to admit this, adventurer, but the orb must be destroyed. The orb is nearly impervious, but it may be vulnerable to the weapon of a powerful demon lord. I have heard that such a blade is present in Ashenvale--at the site where the pit lord Mannoroth was destroyed. Gather motes of the fallen demon's essence there, then shatter the orb upon the blade.