It's a chain of triggers but here it goes: (I hope you can read SF)
THIS STARTS THE RANDOM
Switch(Switch 20, Set);
Switch(Switch 21, Clear);
Bring(P7, AtLeast, 1, L, Anywhere);
-----
MoveLocation(lock, L, P7, Anywhere);
GiveUnits(1, L, P7, lock, P6);
CreateUnit(1, Overlord, lock, P8);
KillUnit(Overlord, P8);
SetSwitch(Switch 23, Randomize);
SetSwitch(Switch 24, Randomize);
SetSwitch(Switch 25, Randomize);
SetSwitch(Switch 22, Randomize);
SetSwitch(Switch 21, Set);
PreserveTrigger();
Comment("i-randomizer");
THIS IS ONE OF THE OUTCOMES
Switch(Switch 21, Set);
Switch(Switch 22, Set);
Switch(Switch 23, Set);
Switch(Switch 24, Set);
Switch(Switch 25, Set);
Bring(P7, Exactly, 0, AnyUnit, lock);
-----
Comment("i-outcome 01-uraj");
CreateUnit(1, Uraj Crystal, lock, P7);
GiveUnits(All, L, P6, Anywhere, P8);
SetSwitch(Switch 21, Clear);
PreserveTrigger();
HERE IS ANOTHER OUTCOME
Switch(Switch 21, Set);
Switch(Switch 22, Clear);
Switch(Switch 23, Clear);
Switch(Switch 24, Clear);
Switch(Switch 25, Clear);
Bring(P7, Exactly, 0, AnyUnit, lock);
-----
Comment("i-outcome 05-crysalis");
CreateUnit(1, Young Chrysalis, lock, P7);
GiveUnits(All, L, P6, Anywhere, P8);
SetSwitch(Switch 21, Clear);
PreserveTrigger();
The problem is that it will often create 2 units instead of just 1, which leads me to believe it's somehow doing 2 outcomes for some reason... You might have to look at the map to get into any more detail.
EDIT: Here ---->[attachmentid=20296]