Honestly, I think the hardest boss in the game is normal Diablo, specially for a necromancer. I normally play a summon necromancer, and he is the only boss I have trouble beating by myself.
I normally play softcore when I play online, however, I play my characters like they are hard core players… Probably helps that I normally play a summon necro, the only character who can beat the game naked.
I dunno, it seems like each of my chars dies stupidly. I remember a few oddball deaths, like a random boss in nm act 2 that slaughtered my pally, and my sorcs tend to die at least once in act 1 jails (nearly always while they have to melee before they get their target spell.)
Especially since his red lightning doesn’t have a “donut hole” yet in Normal. In NM or Hell, if you’re close enough to melee him, his red lightning won’t even touch you, but it will in Normal. A decent melee build should still be able to kill him, though, if you have a little crushing blow.
Oh, as in no hand-me-down equipment, just what you’ve found yourself? I did one of those once that was able to solo Über Diablo at level 50, just to prove that it could be done. Admittedly, that was pretty much the only thing that character could do: Three or more Fallen was enough to make him run away like a little girl.
I second trapsin
Get lightning sentry first. Then death sentry, just for the CE.
Get in the habit of throwing 4 lightning sentries, then 1 death sentry. Lightning gives the damage, death gives the occasional bonus of a corpse explosion.
Max lightning trap first (and get most synergies) - then pump fire blast for a secondary source of damage (it has lots of secondary synergies)
Use the shadow tree for survivability. BoS, fade, SM, SW and WB all have value. Tweak to your playing style.
Finish with maxxing all lighting sentry synergies. Then shadow skills, until you can survive and roll. Then death sentry synergies. Last, fire blast and its synergies for a secondary attack in hell where things might be immune to lightning.
Update: I stopped Amazon (named BoreAzon) after like level 12, and made a typical lightning sorc up to level 55. In the beginning, it was hard to throw stuff away because I wasn’t allowing muling, like marginal rare javelins, or low level leech rings, that I knew would be useful on new characters, but after a while, it felt very free and relaxed.
But, as usual, boredom was my demise. I was on cruise control all the way through nightmare (although I almost died because I tp’d instead of attacked to that rune boss in Act 1, had to escape/quit.) Somewhat of a close call on Andariel and Duriel, but made it through easily. Then, I died on an extra fast boss in act 3 because they were extra fast, I was trapped in recovery, and my merc was jerking it in the corner.
Not sure if I’ll try again soon, it’s just far too boring. I almost died a few times through act 2 and 3 because I was so bored I just tp’d blindly, tanking potions.
Don’t forget about Mind Blast, either. That’s my standard “panic button” when I’m playing an assassin: There’s a good chance of converting some monsters (which both keeps everything else busy for a little while and eventually provides some corpses to Death Sentry), and even if you don’t, it still stuns them in an area of effect. But note that you can’t use Burst of Speed and Fade at the same time, nor Shadow Warrior/Master. And you shouldn’t really need to pump any of the shadow skills: With enough +skills on gear, they should all be to the point of diminishing returns from just a single point in each.