So, I'm afraid your party caller is at a loss here. I am very loath (? = unwilling) to pick one particular plan, as it's such an important battle (life and death!), and we now have, what, 3 different locations and several tactics up for discussion?
I am getting a bit of cold feet on my own suggestion to barge in and focus on hitting the cleric fast and focused, since I am afraid he's got too many hitpoints to get down quickly, before the melees are swarmed by zombies? Would a quick entangle from Kassius solve that, if we get them distracted far from the entrance, and Logan and Alohan both storm towards the cleric?
BTW, John, how fast can a person run from the barred double doors to the entrance to the BBEG HQ?
I can't figure out if your idea is the best, Kassius, getting the zombies out in the central room and trying to fight them one by one at the entrance door (H3). From our first battle I feel we had a hard time getting them down fast enough, so 12 zombies (+ a healing cleric) will eventually get us down. Celene won't be able to hit more than 3-4 with each channeling at that position. What do you think?
I've made a map with coordinates to make references easier:
I have thought up yet another alternative below, a combination of most of your tactics and ideas we've got so far. I don't know if that could be of use.
Another alternative:
I my own mind, if we instead are to lure them out, our top most priority would be to get the zombies separated from the cleric. If they stay together, and we can't get to him, I fear we're finished. What do you guy think of this?
Main idea: lure all the zombie out, let two hidden attackers (Logan and Alohan) deal with the cleric lagging behind. This idea comes from how he stayed back during the first battle, letting the zombies go close with us, but staying behind himself to be safe and heal the zombies. He'll do that again, I bet.
So, e.g. Kassius barge in the undead-room, and fire at the cleric if possible, to get him riled up. Perhaps Celene uses a channeling to hurt them too, just for good measure. The main group then retreats quickly, but slow enough to let the zombies follow to the large central room. I am sure the zombies will go for us, as soon as they see juicy meat. But we need them to get really far from the cleric. That is Alohans job. He stays in cover behind some crates or stuff in the corner of the North west room (square B4) - I don't fancy the zombies have some 'detect life' ability, right? Logan has Hide from undead cast on him, making him invisible from the zombies for sure. He stays behind the column (D3), seeing when the last zombie comes through. Once it's past the door (D2/E2), he calls out to Alohan to come forth, and he gently shuts the door behind the zombies (so they won't hear Alohan and can't get back anyway). We can't be sure the cleric sees logan or not, but a shut door followed by Alohans commanding voice should stop him. Alohan tackles him, while Logan secures the door with stuff we have piled behind the pillar.
The rest of the group goes behind the double doors (M6/N6), far enough from the evil cleric. We bottle up the zombies in the south east corner of the central room, which we've prepared for them. That would allow Celene to use channeling most efficiently.
As with all the other plans, lots of things can go wrong...And dangerous splitting us up. And we don't know all the cleric has in store for us.