How about making it summon additional serpent eggs for each Beast champion you control? Something like +1 egg for every 3 Beasts. And if there's a Snake Charmer in play, it randomly summons either Constrictor Serpents or Poison Serpents instead of the eggs.
Mke it 10/15 nora, or make it like Brooding season or whatever the Firk it is, basically spawn multiple relics in random places in an aoe 4.
Something similar to Hatching Season would probably work. 10-15 nora would be bad due to adaptive KF.
Yeh, I sorta guessed that's what mods think, cause there's no spells under 20 nora, but it's worth a try =D