Among other arcane spellcasters, Wu Jen is, probally, the least mentioned because of how little official support this class has (Complete Arcane which introduced it + Complete Mage with several new spells) and because it is, basically, less efficient, fluffy Wizard. Nonetheless, even through it is surely not a Tier 1 material (either a weak Tier 2, or strong Tier 3), this class has several unique and truly solid spells (like Body outside Body, which, as I recall, only has a PSIONIC counterpart (the Fission power)) and such. Some of those unique spells have weird mechanic or require Wu Jen to be MAD (like, the Scarf line of spells), and some of them do not have a good obvious use, but potentially may be gamebreakers. The Cloud Chariot spell is, as far as I can see, just that
It is an 8th level Water Wu Jen spell which reads:
When the spell is cast, you and any willing creatures you touch lift into the air on a magic chariot formed of cloud, then fly away in the direction you desire.
You can bring one Medium or smaller creature (carrying gear and objects up to its maximum load) per four caster levels.
A Large creature counts as two Medium creatures, a Huge creature counts as two Large creatures, and so forth.
A cloud chariot flies at 10 miles per minute, so that you can cover a distance of 100 miles over the spell's full duration.
You and your passengers feel none of the effects of this swift movement, though, and the ride is perfectly steady and calm in even the worst weather.
When the spell is dismissed, the cloud settles gently to the ground and dissipates. Should the spell duration expire while a cloud chariot is still aloft, the magic fails slowly, with cloud and riders floating downward 60 feet per round for 1d6 rounds.
If the cloud reaches the ground in that amount of time, it lands safely.
If not, it falls the rest of the distance, and all creatures riding in it take falling damage.
A cloud chariot descends slowly if the spell is dispelled, but not if it is negated by an antimagic field.
Material Component: A small ball of cotton.
Now, the obvious use of the spell - transportation of the party from point A to point B - is not quite that good since both Teleport and Greater Teleport are avaliable to Wu Jen at 5th and 7th spell levels, and besides the situations like getting to some dimension locked place, the Cloud Chariot with its limited range and higher spell level is, of course, inferior to those two. Through, there is still one other use of this spell: a battle transportation.
The casting time is 1 Standard Action, the speed is 10 miles/minute=1 mile/round and judging by the text of the spell, directing the chariot is basically a free action. That means, that unless the battlefield is more than 1 mile in any direction, you are there, with all (or at least some) of your friends, all able to full attack, blast and whatever else you want to do.
The question is: do I interpret this correctly? Is it really that useful? Do the passengers of the Cloud Chariot provoke AoO while moving this way (they are able to defend themselves, it's the Chariot that is moving)?