I've played wizard for a long time, but I just recently found some spells that really help with some problem enemies.
1) spiders: slow, then when they get closer waves of exhaustion. Lets you pick them off after you've landed your aoe necro spells on them and you're waiting for your spell cooldowns on individual necro spells. Slow isn't one of our stronger spell schools normally, but spiders have lower will saves. It landed most of the time for me in r4s with a 100 transmutation DC.
glitterdust: while it is supposed to blind them, they still ended up killing me in testing. glitterdust does work on constructs though which is still handy.
sleet storm: didn't work at all for me. i think it might be due to them having an internal Freedom of Movement buff or something.
stinking cloud: my conjuration DC is too low for their fort saves. didn't work for me.
symbol of stunning: this works well, but it's got a really long cast time and a really long cooldown.
2) kopru red-names: globe of invulnerability and make sure you just stand there.
This will block your death aura but not greater death aura, but more importantly it prevents most of the spells they throw at you including the dreaded ego whip.
My old method of running in circles and chugging gloomy pots of restoration is no longer needed!
3) death-warded feytouched champs: contagion-blinding sickness. since our necro dcs are high, this works on pretty much anything not undead/construct/oozes. cast it on any champs to make them irrelevant while you cc the rest of the mob. gloomspear also works but I usually need it for enemies that have broken through my cc. only downside is needing a level 4 spell slot.