During today's game my character suffered a twilight episode and learned a spell that borders on the useless which I find fantastic.
Faerie Fire
CrIg 10
Voice, Moon, Ind
Makes the target glow with the strength of moonlight.
(Base 1, Voice +2, Moon +3)
Have your characters learned any odd spells from Twilight episodes? If so, please share them here.
At some point, I had a player learn Wizard's Eclipse. He was like - so apparently, I now know how to blot out the sun 
Duration: Moon?!?! That seems like it might be overkill -- but you did say it bordered on useless. I would have expected D: Sun and T: Group for the same level.
Not to be a spoilsport, but Twilight is a sufficiently "costly" experience that in our troupe we always make sure positive effects coming out of it are adequately rewarding. Our players would feel cheated otherwise.
That said, Twilight-learned spells can be rewarding even if "useless" as long as they bend even slightly the rules of magic, and serve as the basis for future research.
That's useless?
Seems very useful as a lamp, if you shutter it when not wanted.
Except the intended target is a person.
OK, that's not clear from the description. Is the spell restricted to bodies?
It's a Creo Ignem spell. Usually, the target is whatever the caster designates.
However, then it's still useful as a curse. Who do you really want to annoy?
Alternately, who do you want to assign a halo/nimbus to?
It should affect any Individual, but that makes it more hilarious, and not likely to be a spell most Magi would ever develop.
The Taste of One's Own Tongue
InIm 1
R: Per, D: Mom, T: Taste
For a moment, you taste the taste of your own tongue.
Doesn't this need target Part? Having this available as a level 1 spell seems overpowered, I think 2 is much better balanced.
It would if it were InCo, but it's InIm - Dolabella is detecting an abstract idea "The taste of Dolabella's tongue" as opposed to tasting all of Dolabella (base 1) and then filtering for only the tongue taste (+1 part). The platonic idea of "The thing my tongue tastes like" as it were.
If it's cheaper to taste one's entire body, sure, let's go with that.
A spell that determines if the target has the Gift, by way of licking, from a snake-themed Twilight episode.