might be stun but i noticed something different when playing Broadside assassin
to be exact, i was doing void with broadside and mobs kept ketting hit until everything on screen died, also all people on game said that "there is million broadsides on screen" This stopped happening when i switched segnitia to sbs, so imo it's strongly connected to time strike proc, since time strike had skill timer when it was in assassin skill tree iirc.
It's worth to remember that the skill itself has very complicated mechanics and %ctc with any timer might interrupt proper working of this skill.
i'm 100% sure it's because time strike proc, but if you use time strikes with meshifs iron parrot, you can cast one broadside and walk around when everything is getting magically killed, and i find this really cool and fun xD