What spell effects are not ingame? (ie restore magicka)

"Corprus"
Resist Corprus (utterly useless)
Vampirism (in the form of a spell, not just an effect... does that make sense? lol)
Summon Rebecca Black
Remove Curse

and.. yea thats all i can think.

Sure there are some Bloodmoon "spells" that shud be included here. Or something.

Morrowind:
Fortify Maximum Magicka (only available through racial bonuses and birthsigns)
Stunted Magicka (exists only as part of The Atronach birthsign)
Summon Centurion Sphere (have to read the book "Secrets of Dwemer Animunculi")
Sun Damage (given by becoming a vampire or wearing the "Mantle of Woe")

Tribunal:
Summon Fabricant (have to be wearing "Barilzar's Mazed Band")

Bloodmoon:
Call Bear and Call Wolf (need to complete several quests for the Bloodmoon Main Quest as a human)
Summon Bonewolf (need to do the Bloodmoon Main Quest as a werewolf)

Also "Fortify Attack" is very rare, if that counts for anything.

Hope that helps!

funny thing i bought resist corpus when i first started playing morrowind. Anyway back on topic.

Pretty much this whole list.

"There are only two ways to get this disease: during the Sixth House Base mission during the Main Quest (this is completely unavoidable) and during the Disease Carrier during the Tribunal Temple quest line (this is a game breaking bug). "

Technically you could use it during this quest.

But elsewhere it is indeed utterly useless.