Does the triggered ability happen before battle cards are flipped?
[Source: WotC]
Yes. You’ll get to plan and set up your flip. The ability happens just after Optimus Maximus is chosen as the attacker or as the defender.
In a previous round up you mentioned that if Ion Blaster of
Optimus Prime was played on Optimus, then he was combined into Optimus Maximus, the Combiner could keep that weapon, however not if he was already formed. I’m assuming that also works with
Laser Cutlass? Play onto an Aerialbot for example. Once combined, does it carry over?
[Source: WotC]
Yes.
Since temporary effects applied to individual members of a
Combiner team carry over to the Combined form for the turn, what happens if I have two active Sentinels, transform Wave 2
Ironhide in my KO area to give them Pierce 2, then play the
Sentinel Enigma to combine them? Does Optimus Maximus then have Pierce 2 or Pierce 4?
[Source: WotC]
In this scenario, Optimus Maximus would have Pierce 4.
Yes.
The enigma cards mention a
Combiner keeps an upgrade in each slot, but here's a weird scenario involving that: Say
Prowl, Strategic Mastermind is upgraded with a
Power Sword. Since he's a melee character, he can obviously take this upgrade. But could you keep that Power Sword on Optimus Maximus when he combines, even though he's a ranged character?
[Source: WotC]
Yes.