Remember you've got unlimited shouts to abuse, if an enemy can even reach you it's very surprising.
Defensively, you've got Dismay, Drain Vitality, Frost Breath (with the book), Ice Form, Marked For Death and of course, the ultimate shout in the "get the hell away from me filthy caster" uncatalogued, Unrelenting Force.
Remember you've got unlimited shouts to abuse, if an enemy can even reach you it's very surprising.
Defensively, you've got Dismay, Drain Vitality, Frost Breath (with the book), Ice Form, Marked For Death and of course, the ultimate shout in the "get the hell away from me filthy caster" uncatalogued, Unrelenting Force.