Armor Spider isn't actually too hard as long as you have a decent shield, block tank the fireballs to get up to it. Stand in front of it just out of squish range and block its leg sweeps until it does the squish, then lunge at it and get your lumps in. When it charges up its big fire breath run like stink back to the fog gate, then repeat.
Use Sticky White Stuff to maximise your deeps.