Compounding Power Trait in the Illusions Line
Blackgate: Zera Mithrandir- Reaper| Zera Targaryen-Mes|Zera Naharis – Ranger|
Considering that each shatter sets your Illusions individually, I would believe the first clone to pop shatters with +9%, the second with +6% and the third with +3%, unless you pull out two more Illusions in the time your others are going in to Shatter (Once you hit shatter you are able to immediately start making more Illusions, even if your old ones haven’t actually popped yet) to maintain the missing % bonuses.
This is just conjecture of how I would assume it works, though. It would be hard to test this.
I’ve read in multiple places that it does affect Shatters. Sadly, I have not had time to test this myself.