Warhammer 40,000: Rogue Trader

Pretty straight forward. You have to stand inside his bubble of protection to damage him. Stand inside his bubble and attack him to get his wounds down. As you are doing this, he will keep placing his exploding glyph attack under you on his turn. After he does this, move away without attacking him. On his next turn it will explode and do damage to him. Keep repeating this until one of his attacks kills him. Just don't attack him yourself if his wounds are low, just bait his attacks.