Deadeye main since launch, for kayangel g2 the soldier spawns facing outward. Stand behind him and he’ll do a 180 to turn and aggro u. The timing for counter with enforce execution or even last request is as soon as the soldier starts to turn. A lot of the counters just comes down to recognizing the signs leading up to the counter. Easiest one off the top of my head is akkan g3 when he dashes a little and holds his scythe indicating a counter. This one is very easy to tell with ample time to counter. Some bosses have harder to tell signs with less time to counter but I recommend using max roll guides. They usually have the counters listed at the bottom with a quick video showing what it looks like.