Bonehew is the third boss in Deepstrike Mines and is one of the more challenging ones you will encounter.
Seismic Disturbance: Envelops the target in a cloud of green smoke damaging all allies within the smoke.
Seismic Push: Deals 1k cone damage and knocks target backwards.
Split: At 25% he will split into two bosses with the same strengths and abilities as the full boss.
You will want to find yourself a grouping of barrels to sit next to for this fight.
So what you are looking at is a bunch of boxes and barrels around the room. You will want to situate yourself near a box or a barrel. This way when the boss does his knock off you will be safely taking damage by the barrels.
Every ranged is going to want to do this and spread out around the room so to avoid area of effect damage from the green cloud.
The boss is tanked in the center of the room. Every now and then he will charge in a direction. This is dodgeable, but trying to dodge it risks getting knocked over the edge of the room. If you are attempting to dodge it move closer to the middle of the room to minimize the risk.
At 25% Bonehew will break into two bosses of equal size and strength. They have all of the same abilities except they will hit their knockoff at different angles. This makes finding your barrels to block it with imperative.
It also does not matter which boss you kill first, just make sure to focus down one fast.
Boss ends after second half dies.