Hard fight because the ghoul is borderline cheesing the party with its bugged move "wolf portal". Some tips that may help:
As one stated previously, take out the skelly bomb first. For better efficiency, it's advisable to do so before battle engage, with a stealth character. A flame arrow between the archer and the oil/ooze barrel can trigger a chain reaction taking out the 2 archer and the skelly bomb as well as damaging one wolf.
Abuse the 2 oil barrel near the lighthouse wall. The torch in the area can set alight the oil from a broken barrel. A right placed teleport on either oil barrel can easily kill 1 wolf and damage the ghoul and another wolf.
If a wolf is dead, the ghoul will "waste" a turn reviving it. However if no wolf is dead during its turn, the ghoul will then do its wolf portal cheese combo, which is almost a guaranteed death for any character in hard difficulty.
Stack up poison res.
Engage the ghoul in melee range to prevent it from using its teleport move.
The revived wolf hit stronger and tank more. Its preferable to stun them and kill them last. If you want to kill them fast, avoid physical damage as they bleed poison which heal them. Despite the rain, any fire move is highly effective (flare, midnight oil etc...)
