It's an okay concept, but has many flaws.
There is a deep imbalance between you and your opponent, since you both play by different rules. In particular, the opponent's only "strategy" is to just stand around and do nothing, hoping that the player screws up for enough turns to unleash an attack. But since you have unlimited time to think, the only way you can lose is if you just randomly click without thinking.
I suggest you incorporate the following ideas:
* Have both the player and AI take turns moving pieces.
* Have Player and AI play by the same rules for charging attacks.
* Have matches cause minor damage to the opponent.
* Add a 15-second time limit to each turn to keep the pace up.