Here's what I think of it. As you can see, I moved the Reaper > Alliyp to be summoned from the Wicca ring (whatever we end up naming it), and I replaced the Bahamut with a Balrog. Either the Imp or the Morlock could probably afford to go, since they're both supposed to be the cannon fodder, right? Also, I removed the Grag and the units that came from him (seemed unnecessary). As for stationary defense units, do there really need to be both a Fury of the Tiki and an Earth Serpent? What are a Tartaro and an Alliyp? An upgrade called Magik? The Tower of Wisdom and the Energy Fountain could also stand to have much more sinister names. Tower of Pain and Fountain of Blood, perhaps? What does a Time Orb have to do with air and fire magic? I'm still not too sure about the Baphomet, either.
Of course, these are all just my own opinions.
First of all, the Morlock and the Imp have separate purposes. The Morlock is for swarming your enemy, and the Imp is effective alone. "Magik" upgrade allows one to build some of the units in the sorcery ring, and also is required for the Tower of Wisdom to attack. it is a good idea, because "Magik" requires that the other two upgrades be done first, which means that only after all upgrades have been finished in the Tower of Wisdom will attack, and there will be no conflicts with researching (I think that the AI was having troubles because if it set to attack while researching something, it had to stop researching).
Renaming the buildings is fine, and the names you proposed are fine. The Earth Serpent and the Fury of the Tiki (I think I will rename it to God's Bane, because it is a cooler name and because it is strong defense) are early and late game defense, respectively. The Tartaro is a heavy melee unit, and the Allyp is a cross between a spirit and a mage.
Also, a new concept for the Time Orb would be just fine with me.
And with the art, it's not my job, but let's see what our artists come up with and then, if they need ideas, go to other games.
