一歩引く - to be physically or emotionally distant from something / a step removed. For example 一歩引いて眺める, look at something from a step further away/ getting the big picture.
From the link @seanblue shared 心を引く seems to be fairly equivalent to 気を引く, which I understand to mean something like ‘be drawn to something’, or rather ‘draw someone’s 気・心 to something’.
The way I understand this phrase, イアル goes into a certain frame of mind for his bodyguard work - without having his attention caught by any one thing, he draws his attention (maybe focus works better?) back a bit - I imagine this like centering in himself, not particularly interested in anyone thing - and tries to ‘feel’ the whole of it.
I think this is a pretty difficult concept to wrap in words, or maybe I just haven’t understood it sufficiently either. To my understanding, イアル enters a meditative/spiritual state to ‘feel out’ the whole situation/environment.
Asking the difficult questions today! Also I didn’t know you could have the big emoticon on here too. The more you know.