For a round-robin effect, on your own guys...
Whether is it Power Word: Shield, Renew or Rejuvenation...
Try something like this.

This is IS Boxer specific.
But since you have that badge, that will work.

Take the mapped key, FTL Target Me, from the General Keymap.
Create a copy of it.

Edit the copy, so instead of using Target: Window - All Without Current as the target.
You have Target: Healer'sName.

So when you push the new mapped key, instead of having all of the other toons (slaves) target the current toon, you'll now only have the healer target the current toon.

Then you make another mapped key for PW: Shield.
You could do this with five steps, because of the five characters.
Basically go Step 1 Do Mapped Key Action (Healer Target Me) Target: Slot 1 -and- Send PW: Shield keybind to Healer.
Step 2 Do Mapped Key Action (Healer Target Me), Target: Slot 2 -and- Send PW: Shield Keybind to Healer.
..........
Since Lax was good enough to include a new round-robin option, I'll suggest going with that.
Create an Action Target Group, that has each of the toons on the team in it.
Create a mapped key, set it to execute a step on press or release.
Give it a hotkey, probably whatever keybind in Wow you use for Power Word Shield.
On step one, we have...
Do Mapped Key Action > Healer Target Me > Target: Group (all of) MyTeam.
Check the box (round-robin within target group).
On Step 2, Keystroke Action > PW: Shield Keybind > Target: The Priest.

In practice, push the key and wait a moment (half a second or so) for latency.
Then let go of the key.
Repeat the process, every 1.5 or 2.0 seconds, so the Priest is not stuck in a GCD cooldown when IS Boxer is telling them to cast the next spell.





(I've actually gone and made ten mapped keys, based on this principle... Slot 1 target me, Slot 2 target me, Slot 3 target me, Slot 4 target me, Slot 5 target me // and // Slot 1 assist me, Slot 2 assist me, Slot 3 assist me, Slot 4 assist me, Slot 5 assist me).
Then instead of using Target: Character - Aethera... I would use Target: Slot 4.
And put the mapped key, into a keymap specific to the team rather than into the General keymap, so the mapped key only applies to the team in question, not every team.