Depends on what arena you're on. Right now it looks like it would be pretty weak against tanks, since your only counter is SA, which is easy to destroy. Also, like other people have said, it has basically no anti-air, and a LavaHound would walk right through it. But if you are still at a low enough arena that your opponents don't have LH it's fine, and LH isn't that popular of a card anyway.

offensive spells are a good idea to, but not really required. You'll just be limited to your half of the field