Originally Posted by
Magdalena
Positioning is key. When you hop up, take Beth'tilac as close to the edge of her web as you can. When a meteor graphic appears at your feet (very visible at even the lowest settings), strafe a few yards left or right- enough to avoid the meteor and hole it makes, but not to move the boss significantly.
Your goal is to get as many of the holes in her web positioned towards the outer edges. That way, you're able to gradually inch further inwards without worry about falling through older holes.
Remember that she will head down either upon reaching 10% health, or after her third Smouldering Devastation. Your goal, therefore, is to get her to 10% as fast as possible.