Welcome to Librarium Online!
Little unsure here with the new rules:
IF a unit (say hormies) begins to fall back due to loosing cc (did not get sweeping advanced)
if no synapse nor opponent is around i do a leadership roll to see if i can regroup(only if above half strength)
if i fail do i cont. to fall back (toward which edge or toward a synapes creature?) or do i now revert to instinctive behaviour?'
if so do i move normally according to this rule or move the 3" regroup movement allowed?
If i pass...well then does instinctive behaviour apply?
do i fall back at all?
fall back, try to rally, fall back more if your fail. if you pass the rally test however, you get a turn free of IB. IB tests are taken at the beginning of the phase, and rally rolls do too - but because rally takes priority it over-rides IB. so you if you succeed, you follow the rules for a rallied unit, and start testing for IB at the beginning of your following movement phase
if you find your self in synpase at the beginning of your turn your rally roll automatically passes, so you move/shoot/assault as allowed by the rules for a rallied unit
at least. that's how i'm playing it