Those who play characters who use magic typically create their own sets of spells. My mages have come up with quite a few in their time:

Fast Access:
Open Very Hard Lock in 10 Ft. on target

Total Concealment:
Chameleon 100% for 30 seconds on self

Summon Bob: (Note: Bob is the name Solina Atrius gave to her Clannfear)
Summon Clannfear for 60 seconds

Summon Atronach Force:
Summon Flame, Frost & Storm Atronachs for 45 seconds (Greater Power spell added by a personal mod)

Summon Skeleton Brigade:
Summon Skeleton, Skeleton Guardian, Skeleton Hero, & Skeleton Champion for 30 seconds (another Greater Power spell added by a personal mod)

Hypothermia:
Frost Damage 40 points for 5 seconds on target

Flame Maelstrom:
Fire Damage 50 points in 10 Ft. for 5 seconds on target (crispy)

Shockblast:
Shock Damage 50 points in 10 Ft. for 5 seconds (that'll make your hair stand up)

Haelia Naga (Ayleid for 'Horrible Death'):
Damage Health 50 points for 5 seconds on target

Tempest:
Fire, Frost & Shock damage 20 points for 5 seconds on target (that's gonna leave a mark)

Acadian's Cataclysm:
Drain Speed 100 points in 15 feet for 1 sec on target, Fire, Frost, & Shock damage all 40 points in 15 feet on target and Damage Health 40 points in 15 feet on target (if they manage to survive the first hit, the Drain Speed effect makes the target 'forget' they were just attacked, which has led to some comical moments)

and a much more powerful version of it:

Acadian's Apocalypse:
Drain Speed 100 points in 20 feet for 1 sec on target, Fire, Frost, & Shock damage all 100 points in 20 feet on target and Damage Health 100 points in 20 feet on target (very, very few enemies can survive a hit from this, but those that can are the type you don't want coming for you afterwards)

^That one pretty much drains the magic meter dry, but it's very effective.


So, what are some of yours?

Lothran has a few too

Mighty Sleipner
Fortify Speed and Acrobatics 100 pts for 20 secs on Self

Natural Disaster
Fire, Frost and Shock damage 25 pts for 5 secs on Target

Ragnar?k
Fire, Frost, Shock and Damage Health 50 pts in 10 ft for 2 secs + Paralyze in 10 ft for 5 secs on Target.

Buffy′s Identification
Telekinesis 100 ft for 30 secs

Protection of Valhalla
Shield 10 % for 100 secs on Self
Restore Health 5 pts for 100 secs on Self

Summon Kyne
Summon Kyne to find Buffy or Lothran, depending who summons her of course

He has many more in his spellbook

Edit: Happy 4000 posts! Only 1000 left before next rank!

Buffy has loads of custom spells. Here are just a few:

Summon Kyne (same spell that Lothran has).

Fear. She simply combined demoralize + turn undead so it works vs anything. This simplifies her hotkeys by only needed one spell to scare stuff away.

Command. Same idea – combines command creature + command humanoid.

Panic button. Summon a very scary friend + invisibility on self.

Horse on the water. Waterwalk on touch x 120 seconds.

Eleanor's Wrath
20 points shock damage, 20 points frost damage. She can cast it about 5-6 times before running out of magicka, which means she can deal quite a bit of damage.

Eleanor's Fury
I believe it's about 60 points of shock damage. Has devastating effects, but is much more magicka-costly.

Vision
100 feet of life detection. For those dungeons that just freak you out!

Decorator
It's her telekenisis spell, so that she can decorate her dwelling with ease.

Lifesaver
Restore health 30 points, fortify health 15 points. When she's outnumbered, she'll cast this to keep herself going.

She's also working on an area-of-effect paralyze spell, which will also have a burden effect (that lasts longer than the paralysis). There's a couple more, but to be honest I can't remember their effects ...

and happy 5,500 to you!

EDIT: To make this post on topic (sort of), I don't have any custom spells because I only played a mage in Oblivion for about 20 minutes aha

Static Shock:
1pt shock damage on touch.
( I used this just for laughs.)

Frostbite:
50 pts. of frost damage and paralysis for 10 seconds on target.


That's all I really remember... I havent played Oblivion for a long while... * Goes to dust off Oblivion and play *

I've only made custom spells for training, such as dispel with a magnitude of 3 and duration of 1 set to 'Self'...

I have a bunch added by mods like Lock doors or Mist Form which let me go through locked gates and doors or Wolf Transformation but I didn't make them so I wouldn't count them. Still have a bunch I made on my own like:

Cattle Care
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Cure Disease on Target
Restore Health 10 pts for 5 sec on Target

Face Melter
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Weakness to Fire 30 pts
Fire Damage 30 pts