And it doesn't really fit Necropolis ideologically.

Here, I must disagree with you! Magic is not tied to ideology in any way (and even with races, everything is quite relative). Here's a simple example: Haven and Castle are representatives of the "good" side, but Haven can perfectly develop Darkness (they have the best Darkness perk), and Castle (simply the "very best") - Chaos. So, what is the connection between the Knights of Elrath and Darkness? And between the "good" Castle and Chaos? That leaves Light and Summoning. Summoning is clear: 2 out of 3 "evil" races capable of developing magic really like it. Now, let's return to Light. Above, I explained quite clearly (and several times) in what situation I used it for Necropolis. I repeat: late game + Lucrecia + access to a castle with Light + Light magic (in my case, a witch hut). I developed it as usual (a very deep late game), but instead of Summoning, I took Light, and I was VERY satisfied! I was simply DELIGHTED with the vampires buffed with Light, starting from the 3rd week, I put almost all battles (except for the 4 most difficult) with ONLY VAMPIRES and went WITHOUT LOSSES. Easily destroying EVERYTHING along the way - all sorts of neutral creatures (sometimes quite strong), all the AI player's armies. The main thing is that it's all very easy and without any tricks - Light for vampires, Darkness for the enemy, and that's it! In the main battle, my opponent (a human player, Dungeon) was simply torn to shreds! I was even surprised myself. I'm not saying that you should always develop this way! There are indeed many "ifs," or rather, 2: Light magic + access to spells. BUT if there is an opportunity, I will now develop Necropolis specifically through Light; IMHO, it is more useful than Summoning and Leadership combined. Regarding the "Magic of Speed" and "Stone Strength" perks. Here, it's a matter of "either/or." There are several options: 1) Take both perks, but only one magic; 2) 2 perks + 2 magics, but don't take Logistics; 3) Take one perk; 4) Take everything, but play as Orson (zombie), Dryad, Vlad, or Nadir. The first option is not appealing to me, the second and fourth are unacceptable (IMHO, late game - Lucrecia, not late game - Kaspar). The third is the most realistic, but again, I remind you that perks spend levels and only give an advanced level of Light (sorry for the pun). And finally, about ideology. As far as I know, Demons are very vulnerable to "weakening," but what if, on the contrary, they are strengthened?