Julian had noticed, yes, and he asked Helena: "Reassure me, and tell me that you are fully aware of the danger that Yelena can represent."
Helena then looked at Yelena and Iris who were still holding hands and talking animatedly together, happiness radiating around them and yet Helena sighed and said: "Do you really believe that a Warrior Spirit can be so blinded by love that he forgets his reason for existing? To protect all those who are unable to fight against forces that come from outside their world and against which they can do nothing.
In the past, this threat came mainly from the Gods, but Yelena is living proof that it's not just the Gods who can pose a threat.
If Yelena can't master this power she has access to, then we'll have to find a way of ensuring that she can never use it again."
Helena then patted him on the shoulder and said: "You're a good teacher, Julian, and you care about your students.