Celestial Dragon/1.03

Celestial Dragons are elite fliers. "Never judge a book by its cover", for If you were to judge a Celestial Dragon purely on its stats, you would discard them without a second thought. With the second highest cost of all Dragons and the nearly lowest stats around (it only has 15HP more than a Frost Dragon, but all other stats match), the Celestial Dragon makes its mark with its abilities. A significant fraction of the units in the game are considered evil, resulting in the Celestial Dragon often dealing double damage to the enemy, effectively giving it a base 80 attack. Further more, this attack is magic based, which only a handful of units in the entire game have any form of resistance to. This means even against non-evil targets it will be likely doing more damage than the other Dragons would be. It doesn't end there, either, for the true icing on the cake is that any unit slain by the Dragon turns into crystals that the owning player of the Dragon gains as resources. This means after slaying a few units, including harmless animals, you gain back the crystal resource you initially spent on the Dragon, plus more. And that's not to mention that Celestial Dragons are found within crystal-hungry races. Failing to take down an enemy Celestial Dragon carefully will end up boosting its player's economy and potentially spell doom for you!

=Factions=

Fey
When Celestial Dragons start appearing by their side, the Fey may reconsider building Crystal Towers to fuel their economy, as the beasts act now as mobile towers and may hunt down any enemy that had avoided the Fey towers until then. Indeed, if the enemy is plenty and a good source of crystal, Celestial Dragons become really cheap if the Fey have a host of Leprechauns to bring their gold in the pot.

Furthermore, any dragon on behalf of the Fey can lead them during base attacks, so as to take care of towers while the high level Fey dispatch most of the opposition, thus questioning the need for additional fire ranged attack. Hence, the Faerie Fire research could well be avoided and Pixies would then keep being a freezing nuisance (they are the only cold damage dealers in the Fey army).

Benefits from Panoply, Lore, and Eagle Eye researches.

High Elves
With its high powered magic breath that turns enemies into crystal and double damage vs evil creatures (a huge portion of the units in the game), as well as its high endurance, Celestial Dragons are simply one of the best none-Titan units in the game. Its cost may be high but with the High Elves having access to Trade, the Celestial Dragon isn't really that difficult to afford. And once it is in the field, it'll start paying you back with the crystal it gains for slaying the fools who strayed too close to it.

Considering that the High Elven spellcasters have frost type attacks and spells, one of which is the Freeze spell, there is no rush to produce a Frost Dragon. So you should wait till you get the extra resources and produce a Celestial Dragon in almost all cases.

Benefits from Healing research.

Knights
Celestial Dragons are undeniably amongst the most powerful of dragons in the game alongside Dragonliches and Frost Dragons. It may be slightly weaker than some other dragons, but its abilities more than make up for all of its shortcomings. Firstly, it bears Magic damage - the most dangerous damage type in the game since it does not factor in armour or resistance. Secondly, it deals double damage to all evil enemies and thirdly, its attack converts its victims into 85 Crystal each for the player to use.

Benefits from Crusade, Armorer, and Order of the Rose researches.

Wood Elves
Although the Wood Elves essentially have access to free crystal via Ancient Wisps, the Celestial Dragon's ability to gain a large sum of crystal immediately upon killing a foe makes it far more valuable. With this ability, plus its magic attack that also does double damage to enemy units, it's no wonder the Celestial Dragon is one of the best Dragons in the game, and one that the Wood Elves desperately needed. Celestial Dragons should be used to harvest crystal to fuel Ancient Wisp productions and, when combined with Magic Wells, can even be used to fuel the production of further Dragons. It may be a costly unit to obtain, but the Celestial Dragon's game changing power and traits simply make it a unit that you should aim to get.

Benefits from Eagle Eye and Healing researches.