I'll preface what I've said before by saying that while I love my myst classes, the "thumpers" have a lot to be desired, especially with the HP boost they get innately, that's huge.
Now, regarding the massive damage I can do to things (even more massive now that I can have spell criticals!) is due in part to the following:
A navel ring (+100% spell damage)
A chefstaff (+100% spell damage)
An Ankh (+25% spell damage)
And more sauceror potions than you can shake a stick at. Those potions usually get me to about +400% on all my stats, which helps on those giant spells. Undampened by hobo-boss modifiers, when I buff all the way up and get my "Spellmurder" outfit on, I can hit for over 8000.
However, consider the cost I would normally incur for all of that: reagents, scrumdiddlyumptious solutions, fruits and whatnot, I pay a heavy price. But that gets us some good gear, nonetheless.
Anyway, I love me my myst guys.
Tyred