Chilling Gaze is a sixth level warlock/wizard spell (p31 of Book of Lost Spells, by Frog God Games). It has no material component cost, casting time of one action and a duration of concentration up to one minute. It's effect is as follows:
Your eyes become cold and frosty. For the duration of this spell, whenever a creature starts it turn within thirty feet of you, you can force it to make a Constitution saving throw. The creature must be able to see your eyes and you must be able to see it. If the saving throw fails, the creature takes 2d10 cold damage and becomes paralysed by supernatural chills. The paralysis lasts 2d4 days; this decreases to 1 day if the victim is warmed by a dwelling, bundled in furs, etc. The paralysis can also be ended by magic capable of removing paralysis.
Creatures that are resistant to or immune to cold damage are not paralysed by the spell.
There's a couple of issues I see:
Firstly, the power (paralysed for 2d4 days on one failed save) is much higher than other sixth level spells. I think I'd like to drop it to paralysed with a save every round to shake it off. (I'd also insert a clause that after saving once you would be immune to this specific casting of the spell).
Second, it seems to break 5E's action economy. Attacking on every opponent's turn seems a little too much. I'm thinking of requiring the use of the caster's reaction, so it will affect at most one target per round.
Any thoughts?
Sorry, I just realised its actually a Necromancer Games book, not Frog God Games. I don't suppose someone with magical, moderator powers could amend my OP?
Maybe require 2 saves, kind of like petrification? Fail the 1st save, paralyzed 1 round, fail the 2nd and become paralyzed for 2d4 days, with a new save allowed each day (Advantage if warmed).
And require a bonus action to redirect it to a new target.