If you're a Keeper with Chain Lightning,
Don't use it. How many noobs keepers out there CL everything before the tanks/dps and get mowed down after aggro can't be pulled off them? All of them, that's what.
The only time to use CL is when they're safely CC'ed within your static cage, and AFTER your allies have already hit them. CL isn't an opener. It is a finisher.
Preferably, don't use CL at all, and stay out of line of sight. Barrier , Static Cage, and don't bloody die. That's the Keeper's role. Veilstrike for advanced keepers, but it certainly IS NOT DPS.
Sometimes, I do nothing but barrier and SC, and hide behind a wall. That makes me over 2x as effective as every mobile keeper out there due to winter's stillness giving me 1.5x bonus to both mana regeneration, and cooldown recovery for all spells, giving me 90% uptime for both barrier and SC, instead of dead allies and enemies running amuck all over the place.
I am also infinitely more effective than all the Keepers dead out there due to exposiving themselves to archer & horror fire to try to do minimal DPS from chain lightning.
If you're a new keeper in perilous don't chain lightning at all.