So I'm somewhat new to ADOM

[NemoTheAxolotl]

Okay so the title is quite misleading. Got the game last year but recently got into a really nice groove over past few months. I played casting classes from the beginning despite being told they weren't for beginners. Died a ton and had good laughs. So far I haven't had a single official win, I had a gate closing Mist Elven Necro at L+, but it was somewhat savescummed because I died to ACW twice since I got really attached to Mycthyus and his frail nature. But now I've been trying to get a proper win with a new Female ME Necro Kara, and this time going the chaotic route. My last attempt was going alright, I got precrowned with Arak's Guard, got healing without killing Jharod because I didn't want my learning below 20 and was just about to cross the AForest when a lightning vortex behind a door exploded when I opened it. Saddening to watch, so I thought I'd seek some advice to avoid any sudden deaths like these. I love to play ME necros and want to get my first proper win with one of these

[Blasphemous]

If you don't mind chaotic alignment, you can eat undead corpses (wights, wraiths, vampires, spectres) to increase toughness and its potential.
With high enough toughness you should have enough HP to survive sudden deaths, such as vortices and the like.
Necros have food preservation so this somewhat increases the corpse generation rate.
If you can, try to max out toughness with herbs first, necros get herbalism by default and herbs are guaranteed.
With gardening you could even start a farm because it's easy to level it up and then you have limitless source of healing. Again, useful in tough spots.

[NemoTheAxolotl]

Thanks for replying, problems is that I really can't survive without the healing skill and unless I have magic missile and some okayish slaves, keethrax is usually tough for me, But I guess I can see the benefits of gardening past the early game, if only the skills didn't level so slowly, I've been constantly picking Alert for TH and hoping for 2 to 3 leftovers talents so I can get Skilled, Very Skilled and Extremely skilled because of how hard it is to upgrade skills

[Grond]

Prioritize getting elemental resistances and higher HP. If you can precrown, get properly crowned as well - you get an immunity and 3 of the 6 possible gifts (preserver, robes of resistance, staff of creation) are extremely helpful for survival. Try to get the elemental gauntlets as soon as possible (you can wear iron gauntlets without taking damage if you have Immune to Pain). Don't waste talents by going for TH - get stuff that actually helps you not die, like Tough, Hardy, the PV talents, and the speed talents.

[NemoTheAxolotl]

I dunno if I could do without TH, it saves me a ton of time when I'm gathering items, but I guess I'll substitute the skilled talents for Tough and Hardy

[NemoTheAxolotl]

Okay I've gotten a somewhat good one going, got healing and changed back from N- to C. Now I'm Doing PC to get some early poolsipping and hopefully getting something good. My major fear is corruption since I'm playing chaotic this time around, so getting a way to save khelavaster would be nice, otherwise I'll do the rift and Bug Temple and try to play fast, even though I never really do that well. Also, is it possible for undead slaves to leave up after they "adjust to your power"? I've seen them level up when I'm at lv 1 and they kill some things, but if they ever adjust to my power, their levels just become stagnant no matter how much I let them kill

[NemoTheAxolotl]

Well the next morning didn't end up so great, even after I trained up slings to level 4 so i didn't have to rely on spells while I still had 2 offensive ones,I ran into a dark elven priestess and her usual posse of spiders, knowing the frailty of my Mist Elf, I proceeded to Frost Bolt them as quickly as possible, the spiders died but the priestess somehow kept shrugging them off until I had about 10pp left, however I managed to kill her before she could take a single point of HP off me.

On the other hand, it turns out there was one tarantula left in the room and I figured, "I usually kill those in three rocks, might as well finish it off" Somehow it kept dodging and got into melee range, so I tried Frost bolt and it still survived, got into a blind rage and took 20 out of my 30 HP and left me poisoned. I knew if I tried running I'd die before I had enough PP to cast Neutralise Poison and I didn't have any slaves left to distract that thing, so my only option was to pray...

"Mortal Ye Art a Nuisance"

Ah right, I sacced at an L altar to become neutral for a few minutes. So after looking to see that it had 4% HP, I tried to just hope to berserk it with my last sliver of health, somehow missed and died. This just reminded me to always have at least one slave to assist my escape

[Cactus]

...got healing without killing Jharod because I didn't want my learning below 20...

The much more important reason to get Healing by killing Jharod than by letting him touch you is the abysmal skill dice Necromancers are cursed with. Jharod will only give you skill value ~20 while Kranf lets you start at 60! And especially as a Necro when you're stuck at +1d3 or +1 quickly, that difference matters a lot.

Some more advice for your chosen combo that might be useful:
Prioritize First Aid and use every oportunity to practice it (in Coward mode obviously). First Aid is pretty cool since it got buffed, and it shines especially for Low-HP characters that do not benefit as much from longterm healing.
Try Candle star sign for the obvious healing benefits or Salamander which gives you a spellbook of Firebolt in addition to Frostbolt. That way you can laugh off early critical threats such as Cavemen.
Use ghuls as slaves. Use troll corpses for them for regen.
When you hear a distant wind, prepare. Vortices are a huge threat as you noticed. One efficient possibility that you might not be aware of is to sacrifice your slave (or homunculus) by commanding them to attack the vortex.
Also, just for fun, try the Heir gift for Mist elven necros once. IMO it actually makes the game harder than three useful talents but it's very unique as heir gifts go.

[Grond]

Salamander which gives you a spellbook of Firebolt in addition to Frostbolt.

Salamander only affects starting spellbooks for wizards. A salamander-born necromancer's second book is still random.

[NemoTheAxolotl]

I got a really Epic one going a while ago, I entered the UCa and immediately saw "You feel a surge of power". Jackpot, an artifact, said artificial was Whirlwind, which was cool since I love slings and I was on a roll, Candle born and Healthy talents meant I could skip healing in exchange for gardening and buff up may stats, unfortunately in the bottom level of Keetrax's Dungeon a Giant Slug Oneshot me FAR beyond what I would be able to survive, and it was just about nearly killing it... It sucked but I had a laugh since this was almost exactly how my early ME necro run ended once, one shot by the acid breath of a lone black dragon.

After some minutes of grieving and rerolling I've started another Female ME necro that got precrowned with Wyrmlance, not bad... But can I just have something cool like armor please? Making sure to be extra super cautious with this gal, not ready to have another good one die on me

Also hoping to get the thorns corruption when crowned to take advantage of shadow touch later I found it really helpful when I had been using it