Why U may ask, Because of LOW mana cost HIGH HP, HIGH SPEED. \
Wait, High speed?!? YES! Because he is so fast is an Ideal front-line evader.
Let me show U an perfect example from my previous battle.
15 MANA battle
I had the drake on front-line, 2 Small assasins, and The Specter.
On Enemie side saw that pump-up Djinn Cwala, I said, ok this is over.
On first round Specter killed the chicken and assasins the spider. Only The Mighty Djinn remained. 9HP 4Shiel + thorns, Mision imposible.
On Round 4 all my hope was on Dragon Spirit to evade at least 4 more rounds. To let the specter do his thing.
At Round 10 Djinn received the final blow from Specter and my Dragon Spirit laughed in his face he managed to evade 9 hits!!!! a 27 Damage evaded, mind-blow.