Actually your character will practice Necromancy quite often during quests, there will be communications with dead, ghost hunting, possession by ghost, bidding souls to your will via necromantic rituals, creation of skeletons and zombies and even flesh atronach, transformation into skeleton by itself and many other examples.

For example, I play both Nightblade and Sorcerer as one character with same name, who changed his class after being posses by ancient Telvanni ghost sorcerer who is encountered during ghost hunting quest in Vvardenfell , but since my Nightblade become Vestige after one of Barilzar's inspired experiments by prolongation of his life and removal of vampire blood craving, those Telvanni ghost was trapped in my soulless body like another nordic ghost who try before to posses that Nightblade character in Windhelm Halls of Dead, I roleplay this as my character become something like Raziel from Soul Reaver and Akachi from Mask of Betrayer, vampire being that was transformed into soul devourer and now hunger for souls.

But also its allow me to roleplay as my character have several personalities as ghost try dominate my will, something like Raistlin Majere have with Fistandantilus or Vaarsuvius have during Soul Splice ritual.

To support my RP with gameplay I use certain sets, Caluurion's legacy set, its create lich like crystals behind your back who shoot into enemy nasty bolts, Nerien'eth monster set create lich like crystal trap but also have some lich like visuals, Bahraha's Curse set creates necrotic rune on ground who slow enemy and drain health from them and transfer it to player character.

I also use certain skills: Soul Assault and Consuming Trap, Invigorating Drain and Elusive Mist, Temporal Guard and Deep Thoughts, besides of class skills of both Nightblade and Sorcerer.

I also use various memento and personalities in my roleplay as well as costumes and hats, particularly I use Vosh Rahk Ceremonial Mask as Guthrag's Mask to hide my undead identity similar to Fane mask from Divinity Original Sin 2, otherwise I use Death Grin Skull Mask as "true face" behind Vosh Rahk Ceremonial Mask, that's works very well with Mind Shriven and Soul Shriven skins and last stages of vampirism, even Psijic mystic tattoo add on top for roleplay as I can switch from them to Mind Shriven and then to Soul Shriven with death grin mask like I have done certain Psijic rites of Moawita to protect self from bad sides of my affection like soul hunger and ritual runes on body broken after resurrection in combat.

I believe I have created pretty interesting and lore friendly character for roleplay.

"We'll make a necromancer out of you yet"
- Abnur Tharn

yeah im still waiting/hoping for a necro class