"I'm ok for both ways but am I the only one concerned by the fact that if we stay here fighting one group, we will be overwhelmed by the other one? About that, there is 3 doors, they can storm us from everywhere.
So my best bet is to leave this temple to take the fight where we can control more their movement. But if you prefer to stay here, I'll give you my 2 coppers.
Can we create a cone-shaped corridor, maybe with the temple's benches, with only one narrow exit pointing to us to reverse the number at our advantage.
I vote for darkness + oil. But we can't face 3 fronts so we must be sure they can't enter by the other doors.
If it is possible to disable the ward, maybe we can hijack the trap to make it burst when they'll open the door to flank us.
We must block the south door with everything we have left, even bodies.
Whatever you decide, during the fight, don't stand on the Bhaal symbol, it's bad luck. Trust me I'm a wizard."