Automaton Spider was the core of my team, it's increasing speed means it eventually is taking 4 turns per enemy turn. This is broken in combination with the Attack Interception expansion. The other expansion I went with was Computation Lock for a free 75% attack.
The overlord unit I used was the Aurumaton Gatekeeper. If you equip it with Saturated Activation and Sudden Injection then on its first turn it can debuff all enemies and massively delay two of them, this gives Spider the time it needs to ramp.
I used Bubbles for sustain, their damage doesn't matter so I equiped them with Firewall and Safe Mode for 100% increased health to empower their heals and soak. I gave them Functional Overdraft so they can heal significantly more often. And since they take their turn frequently they are holding Deep Clean for team cleanse.
My last unit wasn't as important to the team as the other three, but it was a Silvermane Cannoneer. They will always get their max follow ups off if they use skill on Aurumaton turn one and then switch to Spider after that. Their ult can be used to give Aurumaton two energy so that it can do it's AoE Impair -> Sanction Mode -> Imprison combo immediately after leaving Sanction Mode which is very powerful. Backstage Enhancement is great damage for them and Efficiency Optimization let's them always have ult on time.
The Morale Activation expansion is incredibly powerful with this team as every unit is taking multiple actions for every enemy action. I had Aurumaton hold it but any unit on the team could hold it really.
If this team survives just a couple cycles it's basically unkillable, and that is not hard to do with the massive debuffs from Aurumaton and sustain from Bubbles.
Interested in hearing about other people's teams in this event as I'm sure there are many powerful combinations.