The ESF: Necromancy cookie is currently Create Greater Undead. I feel like it could be improved, to be a proper RP cookie rather than a casting of a spell that some classes (Invoker) can't use and some class (Wizard/Sorc/Cleric) will already have ample castings of (via scrolls and regular casts). Plus any non-animator with ESF: Necromancy doesn't get a cookie to use effectively.
Some ideas:
1) Mini-Blight. Just like how -ward has a ritual counterpart, having the ritual for blight have a ESF cookie counterpart might be neat.
2) Advanced curse. A radial menu that gives you access to every single curse might be neat. Maybe make it a 14+(CL/5)+(Casting Stat) DC or something.
3) If we want to stick to a selection of spells, then maybe add a few: Create Greater Undead, Curse Storm, Wail Of the Banshee, Stop Heart, and Greater Bestow Curse.
Though I think a unique cookie would be more fun than a selection of spells. Though, a selection is better if its best for ESF: Necromancy's cookie to be a spell from the spellbook.
4) A special non-random curse storm (you select the curse you want and it applies to the storm), with a similar DC to idea #2; 14+(CL/5)+(Casting Stat) DC.
I'd further suggest that if it was a spell (such as ideas #2, #3, and #4) that it be CD-based (similar to scry). Like a 5-10 min CD between uses? Tho it doesn't have to be.
For the spell ideas #s can always be tweaked ofc, they are just ideas. If as suggested, it'd end with a CL 30 caster having a 20+stat DC, and then lower as the caster goes more impure.