Stats for named NPCs

[NoxRaven]

So I have been in the process of trying to create a campaign in the Forgotten Realms setting. I've been using both Hero Lab and Realm Works. However when putting the information into RW I've noticed that there are many NPC's within the FR setting that have no stats at all to go with them. Such as Araevin Teshurr. Now I understand that leaves me as the DM to roll up the stats but I also want to be realistic about the balance of the game as well. Now in the case of Araevin he is the Grand Mage of the new Myth Drannor and he's also basically half elf and half eladrin(celestial). So I know he's going to be powerful. The question is just how powerful? I don't want it to be over the top but I know he's no pushover either.

[Eldariel]

According to Forgotten Realms wiki (https://forgottenrealms.fandom.com/wiki/Araevin_Teshurr#cite_note-FH-p5-0) he's essentially a half-celestial Sun Elf. Elven High Magic is epic magic so he needs to be at least level 21 (probably much higher) as per usual for Forgotten Realms (everyone of relevance in FR is epic). Races of Faerûn has the Elven High Mage prestige class, which seems pretty much a given in spite of receiving no formal training as of the point of the story. He was accepted though. I'm not sure what prestige classes would really make sense on him as I haven't read the books but probably 20+ish levels in full arcane casting classes followed by Elven High Mage from level 23 onwards.

Same with everyone else; just ballpark their feats, toss together a simple build and call it a day if you need stats for them (you often don't if they're not on screen but if you want to feature the character in your game, yeah, stat 'em up).

[DarkSoul]

Wizard and EHM levels, and that's it. He's not the star of your story, he doesn't need an intricate build.