Double checked; AoO occurs if foe leaves the threatened area. So Darius lands front of trolge and as trolge attacks, he activates his counter which is an unbearable gaze, trolge needs roll reflex save DC 19 or else to suffer blindness for one round. On success, they avert eyes away (suffering miss chance as usual averting some's gaze while attacking). If save failed, attack/effects have 50% failure rate even if they would otherwise be perfect hits (meaning it gives magic missiles even 50% chance to miss).<br/><br/>I edit my post present Darius actual action now that lance tactic not working atm.