Second, the giant was hurt as a motherfucker so I'm not sure why he decided to retrieve when there was Tontik sitting at the giant just waiting to entwine him. Especially since he didn't do the things I said above to make it so Ghrondel wouldn't just come and tag-team him once he got entwined.
Third, rain of stone = shit tactics against ragers. If you want a constant damage spell you don't need to keep up, use vitriolic stream because ragers only get one chance to spellbane it instead of a chance every fucking round you're in the room.