I've been playing SP, /players 8, including bosses. I might have to reduce the players for Baal, though, unless I get some good advice. I'd prefer to keep my pride! I never really played D2 much until now, and I forgot what Baal was all about.
Milwaukee is at lvl 45, with:
poison nova 12, working towards maxing it
poison explosion 1
poison dagger 2
My army killed The Ancients on /players 8 while I watched, bored of casting curses. Baal's minions required me to raise my minions a couple times, but was otherwise OK. No biggie.
Baal evaporates my army and slaughters my merc in seconds. I was able to make some pathetic headway by casting Lower Resist and poisoning Baal. And again. And again. Hiding behind obstacles to avoid getting blasted, casting LR and nova-ing. Baal's health is down a hair! (or is it my imagination?)
In theory, I could kill Baal this way. Just me, and Gumby (for 0.25 seconds at a time). But no thanks.
Edit: And those damn tentacle thingies. Damn them.
Edit: I have no revives, because I'm going for a psn/skellie sort of idea, but could they tank while I sloooooowly poison Baal? I'd have to shop a wand.
I'd say find a way to cut him down to size and cut his speed up. Haven't tried it, but try using a clegaws pincers with a fast bow, this would probably help till you can up your own damage, and he's weird when you slow him down a lot.
Kelpies Snare FTW, too bad you can only get it in nm :(
baal's hoarfrost is annoying, as it knocks your minions back. try setting up a tp right beside him, and reentering to gather all your slaves on him.
cheap mans teleport ftw!
oh ya and stack as much slow as you can(cold, slow items, gumby, decrep)
here are some improvements that i can think of..
shop a wand for a +revive mod. those things provide good distraction against baal.
equip merc with strength polearm/spear for a little cb.
buy lots of pots to keep summoning gumby, since he's the only source of slow you got.
You should have put more points into skeleton mastery. It really helps out your skeletons a lot. Same with the one point in Summon Mage (for cold damage).
One trick is to summon up your army and drop a TP right next to him. Then keep popping in the TP to poke him and then leaving the TP and healing again. If your minions are strong enough to survive the one attack from Baal (although without summon resist and with only 21 total points invested in skeletons, I have slight doubts that they could), then you should be able to poke him to death.
Although you might have to grind out another level or two (or three). At least the one point in summon resist if your skeletons aren't surviving the first attack.
If they can survive the first attack, just keep going through your tp, hitting Amp Damage (or Decrep) and then punching out before Baal can kill any of your minions over and over again. It'll take a while, but with your stack of (albeit flimsy and low damage) minions, you should be able to get through it.
Or just bite the bullet, buy tons of pots, and just go to town on him with gumby.
Cast gumby in his face, don't let him walk up. That will get him using up some casting and movement options before your army gets there. Run away from the tentacles and as soon as you can see clear to cast gumby, do it. Your merc and most of your troops should miss his first attack or two. Once gumby slows him, the second attacks will be a longer time coming.
cast Gumby and decrep right onto Baal, and use the TP trick as noted above to keep things going. with decrep on, he should effectively be slower, weaker - he likely won't raise those tentacles, nor create a clone.
if you don't have a teleport amulet or something, you can cast Gumby and Decrep before you turn the corner onto the platform where Baal is - when you get into the throne room, run down, and then towards Baal's platform; before you turn the last corner to let your skellies at him, you should be able to cast gumby and decrep from the other side of the pole. not sure if that's very clear. ;/
try to avoid casting Amp - you will lose the huge slow effect of the decrep.
did you have at least a point in Summon Resist? that'll help quite a bit as well.