Although I haven't beaten the game yet I am playing it through on hard (please don't suggest otherwise). Nevertheless I find myself stuck unable to fight the party at the lighthouse.

My composition includes an elemental wizard and a marksman + the other two. I've used telekinesis to move the oil barrels closer to the ghoul, poison cloud arrows detonated by fire spells but I'm always overwhelmed by revived pets or the ghoul simply outright teleporting in and wrecking my party. Last time I attempted it, even the walking bomb skeleton didn't move and that didn't even help. I've positioned my ranged characters as well as I could behind the tank as well.

Rather frustrating at this point and I'm out of ideas. My characters are all lvl 4 as well. What am I not considering?