Defiance
As a Blaster loses health, he begins to unleash his true power in a last ditch display of Defiance. The less health he has, the more damage he deals.
Any Wound Point penalties are reversed for Powers attacks; you get a +1 bonus at 25 Wound Points and a +2 bonus at 30 Wound Points. You still suffer a penalty to all other skills, including Dodge.
Build
A blaster uses Powers skill and Super schticks. The obvious power choice is Blast, but Magic Melee is very common as well. Blasters generally put all they can into Magic but go light on defensive powers.