so...a comparison here
phase dragon
8|6 for 13 quanta
8/13 = 0.615 damage per quanta
elite phase dragon
10|6 for 14 quanta
10/14 = 0.714 damage per quanta
demigod
11|11 for 17 quanta
0.647 damage per quanta
mortal demigod
9|10 for 15 quanta
0.6 damage per quanta
so...from that we can see that the UPGRADED, RARE card is the least powerful? The hp difference means hardly anything. Against a fire buckler, phase dragon deals 48 damage and elite deals 60 damage. That's enough to kill them with 2 dragons... against thorn carapace...
turn 1 - phase dragon deals 8, then gets poisoned for 1 (using the worst possible luck for the attacker)
turn 2 - 16 damage total, 5hp, 2 poison
turn 3 - 24 damage, 3hp, 3 poison
turn 4 - 32 damage, dead.
so at worst, an unupped dragon deals 32 damage... or 28 if they have an upped shield
so this card is like a slower phase dragon that's ever so slightly tougher... it adds nothing to aether as an element, therefore i find it kinda boring...