Solo Necro/Mage - not for the faint of heart or slow connection
Your going to have to work mainly on the outside of the spawn, everything except the Serpentine drags is going to zone on you. Best bet is to work from outside up grass pathway to try to clear path to altar for when you want to get up their for Champ later on.
1st Level I find it best to throw forward an EV and then wither spam around it (can really get away without EV but is handy when Paragon Sprite shows). Quite often the sprites(pixies) will either poison/paralyze you when they die, so dont overextend yourself it can be a bad thing to be paralyzed and watch a swarm come in and flay you with a mass of spells landing at once. Personally love the poison as I will run in and try to wither a few then retreat to heal - the poison does little damage and will release you from any paralyze.
The Kirins/Unicorns usually a flamestrike with an EV will drop em, for me 3x flamestrikes if no EV - dont get tempted to go for a lower spell when almost redlined as they will usually get a heal off.
Paragon Wisps/Kirins/Unicorns - best to drag off, invis and just keep dropping EV's on em to kill, if you move or attack they can rezone on you, usually when I get 2x EV's out I meditate as they will kill the EV's and you will need to recast for abit.
Centaurs 2 flamestrikes or 1 EV makes short work of them, Serp drags I usually leave alone they dont bother me and they chew thru an EV with ease, usually other dexers there that like to kill them but if you want to attack stay to attack spells. Paragon centaurs still a pushover but Paragon Serp Drags best to drag off and invis and leave them somewhere out of your way.
The winged creatures are the biggest bane to your necro, they move fast, unload spells with glee, chew thru EV's like your kid eats sugared cereal, just bad news all around. Still working out a good strategy for em, at present I just pre-cast flamestrike, run in drop spell, run off, repeat.
Its kind of a judgement call as to when to run in for Champs, I try to judge how quick we went thru lower levels knowing it will go quick at last level once Serp Drags appear. Pre-cast invis and run to altar, if people havent cleared spawn from around altar you will need to drop EV by creature and then re-invis (if winged creature probably best to lure off). Dont stay to close to Oaks as he spawns pixies and they seem to do area attack that will reveal you. Silvana flamestrike once they have lured Oaks away, then do same to Oaks. If there is too much spawn by altar, cast invis and run back to edge better to hope for event item in pack than risk death and not being able to get to body if too busy