This CW 4-set bonus should give the following:But instead of doing that, it gives somewhere around 60% extra critical severity to everyone in party.Striking a foe with a control spell grants your allies near that foe Reckless Abandon which grants 113 Lifesteal for 10 seconds. Striking a foe with a non-control spell grants your allies near that foe Measured Spellcasting which grants 5% Critical Severity for 10 seconds. Allies affected by both recieve double the benefits.
So you're running with ~140-150% crit severity. For Geared CW this means you will be shield+steal time critting the adds down in second. For others like TR, this means he will lustfully moist hes/hers pants, downing bosses in notime.