Hello, is a spellbreaker still viable? Is there anybody playing an good old glass cannon? If yes please post your cold killers 
It depends on how you define viable. They should be ok for campaign.
This:
http://www.grimdawn.com/forums/showthread.php?t=67508
Haven’t tried it myself. From my experience of playing dozens of builds in GD this one should be able to faceroll campaign and gladiator crucible till wave 150 and then have extreme problems after wave 150 (like all dw builds).