Off-damage

Off-damage, also sometimes referred to as “split”, refers to damaging the enemies outside the main ball so they're low enough to be killed by Edge of Extinction.

In DoA, off-damage is primarily the TK’s responsibility, but it is also the rest of the mesmers' jobs to help in case its multiple sets of off dmg. Usually the standard is the TK as primary damage and IAU as secondary off damage. Off-damage is inherently a team effort to make sure everything gets hit and dies at the same time. Relying exclusively on 1 person is bad because there can be multiple scenarios where a TK cannot handle all the off-damage. In cases where there are too many groups for the TK to hit, you can co-ordinate beforehand who should hit each target. An example of this is 360:

VoR's job is to start spiking the main ball so when the spike chain is finished everything is already under 90 and can die to EoE.

MLK's job is to damage the straggling melees in the back with Wastrel's.

IAU's job is to focus on anything that runs past the wall, using YMLAD + unnat, and to help the TK in case the fiends weren't entirely hit. To go a step further you echo on wave 3 since you have golems on left hill and they are most likely the ones to run around the wall. To go ANOTHER step further, using echo on wave 3 also helps since you can then Esurge the off damage that runs around, and be able to hit the fiends that the TK mightve missed with your second esurge.

TK's job is to always try to hit fiends as they are all within 1 esurge range of eachother. Echoing wave 4 helps incase you happen to mess this up and not hit all fiends at once.

This setup for coordination at 360 works with all variations of tk bars, (SPain,shatter,mimic)