Is this the Calus fight, on Classic I struggled with Hunter so I LFG'd it to finish the regular campaign, Hunter it was crazy on Classic. On Titan it was easy and I beat the campaign Legendary. I ran Witherhoard with Ammit AR2 (Turnabout, Adaptive M) with an LMG (land tank origin). I would fly around in circles using grapple/punch on psions while hitting Calus with Witherhoard. The platform enemies I would use whatever I could to generate special ammo. LMG for the Tormentors. For Second phase Calus I used Witherhoard and finished him with super.