Honestly, I know attack hixboxes are bad on some of the bosses, but the bone dragon just takes the cake. If you move out of its circular explosion and go to around the 7 o'clock position on the map, you might as well just stay on the center, because it hits way past the attack's delimited area there.
Another horrible hitbox is the breath. Both the dragon and the Harbinger hit behind their backs with an attack that's supposed to shoot forward from their mouths. Harbinger's breath also hits way before the actual skill visualeffect comes out, making it really frustrating to dodge away when you're far enough to not see the wind up animation.
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