It’s already included above. You call Restart Timer and feed it the Set ID of the required phase:
This would roll the phase back by 1. Just ensure you do not go below 0 or we’re gonna have a really bad time 
Arrays start at 0.
The object itself is an invisible cone and on button press the cone appears and dissapears, I have placed a sensor on the AI to detect said cone, but I am having trouble figuring out the command to use for the AI to react to said cone (I believe I need to use an ‘on hit’ bp but can’t figure out how to use it).
Use an overlap, as above. OnHit may not work all that well when teleporting and can produce multiple hits - pretty disastrous if we base any math on that - a DoOnce node could help. But proving the cone is not on the move, a Pawn detecting overlap will most likely suffice.