Well, I went and got Monster Manual 1st edition.
Asmodeus seems to be the Satan guy... he's a weakling with 199hp, AC-7, #ATT 1 (Dmg 4-14), 90% Magic Resistance, but has a rod that can shoot fire, acid or lightning, as dragon breath, so I guess that means 199 damage or 99 if a save is made... which is pretty good, and so could ex Loki in 4 rounds and Odin in 5 assuming they don't heal themselves (which they can't do since they are "warlike" apparently).
Baalzebul is less powerful, 166hp, AC -5, #ATT 1, Dmg 2-12 plus poison (doesn't say what the effect is, I'm guessing death if no save), 85% magic resistance. If he looks at you, and you don't save vs. magic, you collapse trembling until 1-4 minute after he stops looking at you.
Which ancient Sumerian Deity did Ghostbusters beat up on?