Vic is only good at 3k TP...actually all WS with 2k+ TP cost should be used only at 3k tp for full power.

Skull Sunder does is one of the best WS of this game...one of my favs also! I just don't use them because of slashing damage type. I prefer using bblunt damage WS as PGL due weapon modifiers (only baghnakhs have slashing modifier). You can use Trammel and Feint too (both from LNC) since many of PGL weapons also have piercing damage...its almost the same as skull sunder, but adding gravity instead of DoT.