Fall Back vs. Beam

[Thoras]

I had a game yesterday where my Cyclops used his beam onto Killmonger, Shuri, ASM. My opponent used "Fall Back" on Killmonger to move him out from under the template and avoid the attack.

I think that Fall Back only triggers in step 11c, so his Killmonger would have had to have taken the hit before moving. Am I correct?

[Thoras]

Just now, Thoras said:

I had a game yesterday where my Cyclops used his beam onto Killmonger, Shuri, ASM. My opponent used "Fall Back" on Killmonger to move him out from under the template and avoid the attack.

I think that Fall Back only triggers in step 11c, so his Killmonger would have had to have taken the hit before moving. Am I correct?

Killmonger would not be able to avoid the attack with Fall Back. 

Fall Back triggers during step 11.b. of the attack resolving against him so it cannot be used when the beam attack is declared (before any attacks are made).

Fall Back does not stop the attack.