I don't think phantoms should be in the game. Their aesthetic really doesn't fit and it would essentially screw over the players who want to join Southern factions like Near Harad, Morwraith and Torathim as it takes ages to travel there. Its already hard enough to have to push through Rohan, Gondor and Ithillen if you want to join Near Harad but being constantly trailed by Phantoms would make it become unbearable.
Another reason Mevans hasn't added dragons is that he can't just copy the ender dragons code and give it a new texture. I kinda presume everyone would like them to be flying around in the northern parts of the world without them having to be summoned. However this would make the northern parts of middle earth almost uninhabitible as you would not only have to constantly be dealing with taking damage from the weather but also having to deal with multiple of what basically counts as an ender dragon chasing you. This means Mevans would have to make them fair and that would force him to code them from scratch. However that would be so much time and effort that would be better used elsewhere.
Personally, I think some form of Big Cat would be a cool Mount, but they're Skelies aren't right for riding, and I don't want this mod to become a Warcraft mod XD
But a large Jaguar would be a cool and fitting Taurethrim mount IMO.
Hey, if you want another animal the aztecs dimesticated you always have the chihuahua...
Perhaps we should give the Morwaith javelins. A type of weapon that is thrown like a spear however has a much shorter range, does less damage and can be stacked to 16. Along side them come the Morwaith javelin thrower which has a powerful range attack but has a very long cool down time between shots.