You will nether get a new card nor gems and recruits (it costs 3/3), so it's not very intelligent to play this card over and over against itself, if the enemy builds up a good wall this card will be useless anyway, but if you play it wisely, it deals a huge amount of damage for a common card...
All in all, it's a tricky card... devastating attack and a nasty side effect...
But I don't like it's long text, if there is a possibility to make it shorter, I wouldd be really happy ^^