General notes are you’ll want to avoid the stun hitting Maneater or Helicath on the first stun.  Place them last in the turn order and ensure you have someone of weak and/or neutral affinity ahead of them with at least one being green affinity (to avoid Hellcat taking the stun).

UNM Setup
Seeker works on a 3 turn delay (a1, a1, a1, a2) or a 5 turn delay if he gets stunned (a1, a1, a1, stunned, a1, a2)
Helicath (or Tower, Warcaster, Sir Nicholas) needs to time the a3 block damage skill to block the first aoe and a 3 turn delay works (a1, a2, a1, a3)
Maneater opens with his a1, then a3

After those delays are done it’s full auto by the end of turn 2 (turn 3 if Seeker get’s stunned) syncing by turn 7

Nightmare Setup
Seeker works on a 5 turn delay (a1, a1, a1, a1, a1, a2)
Helicath (or Tower, Warcaster, Sir Nicholas) needs to time the a3 block damage skill to block the first aoe and a 3 turn delay works (a1, a2, a1, a3)
Maneater opens with his a1, the a3

After those delays are done it’s full auto Syncing by turn 7
DISCLAIMER: Helicath’s passive places Increase DEF and after further testing, on void affinity it’s causing the stun to goto Maneater for the first 2 stun hits. So a work around this is a 7 turn delay on Helicath’s A3 (A2, A1, A1, A2, A1, A1, A2 then you can auto)

Brutal Setup
You will need to actively avoid Seeker taking the stun, anyone else is a valid target.
Seeker works on a 4 turn delay (a1, a1, a1, a1, a2)
Helicath (or Tower, Warcaster, Sir Nicholas) needs open with their a3 skill
Maneater has a 2 turn delay on the a3 (a1, a1, a3)

After those delays are done it’s full auto and syncs on turn 3