The Tavern

The change wasn't made because of flavour, but because of gameplay. Single school L9 was too easy to cast and tornado is very powerful.

You at least have to play a conjuror to use it now, at least. Before, Repel Missiles, Deflect Missiles, Swiftness, Levitation, and Flight were a core part of nearly every character's training regimen partly because they are so good and partly because they are natural steps on the way to Haste. Once you've trained Air enough to cast Deflect Missiles, training it up higher to get Tornado is actually pretty easy.

Training conjurations from scratch is harder, and since you've probably already built up some other means of fighting at range when you need to, it isn't very rewarding on the way to the top. You already nigh-invulnerable crusader or transmuter is going to have to find some other way to clear Ziggurat levels with one spell.

If there's concern about Conjurations being too powerful, perhaps Tornado could be Translocations/Air instead? Might consign the spell to Shatter-levels of 'nobody will ever have the skills to cast it,' however.

Actually, I'd kind of like to see Levitation, Flight, Repel Missiles, and Deflect Missiles be Tloc/Air, so that there'd be an element that has good synergy with Tloc... though putting Deflect Missiles in the same school as Phase Shift would probably be a bit silly.

Translocations is already one of the best schools, and if anything it needs a nerf. Teleport Control + Blink trivializes Pandemonium. If you have Controlled Blink castable, too, then there's nothing in the game that can kill you except Ziggurat cage matches.

Conjurations may look like a big and overpowered school, but almost all of the spells in it are basically the same. They are a big hammer that you drop on monsters and make them stop moving. Once you've got a couple generally good workhorse direct damage conjurations, there's no point in learning any others. Adding conjurations as an additional school to another spell makes it harder to cast, since you have to spend twice the xp to use it. It does make it easier to shift over from (for example) ice conjurations to air conjurations, but there's not really much reason to actually do that, since Throw Icicle and Bolt of Cold will carry you through a 15-rune game anyway.

There are a few exceptions to the rule that probably shouldn't be in conjurations, most notably Mephitic Cloud, but for the most part training conjurations is the toll you have to pay if you want direct damage magic, and it doesn't do anything else.

I understand the reasoning, but I do not really like it. If you must pay conjurations for dealing damage, than what about Shatter? Also, the game as a whole will benefit much less from this awesome spell - because conjurers already have two level 9 spells to learn. Giving a 3rd option to conjurers instead of other type of mages is a waste in my opinion. I'd like to see this spell in use on other type of mages than conjurers.

Here's some idea - just brainstorming:
- nerf the damage but give the affected monsters some status effect, like make them distracted 1 in 3 turns. Change the spell to hex/air.
- nerf the damage but make the duration a little longer. Change the spell to ench/air.

Requiring everyone to get conjurations makes everyone a conjurer. This is boring and it reduces variety in casters.

I don't see why just nerfing tornado isn't an option.

I decided to make a test character in Wizard mode to see how far I need to train my Air Elementalist so he'll be able to cast tornado.
The test character is a level 20 High Elf, has 27 Int, ring of Wizardry, Conjurations at 17, Air Magic 18...and Tornado is only at Bad. What the hell? If I ever survive this far with my actual character, why would I even bother learning the damn spell?

It's a dual school level 9 spell. Those are the most powerful spells in the game, and you need to have the requisite skills near the maximum level before you can reliably cast them.

Get air, conj and spellcasting to around 20 and you should be able to cast it. If the success rate is at "bad" that means you only have a little ways to go before the spell is usable.