from what i could tell by the raws; it’s a mixture of both jealousy towards the saviour who casted the barrier (which is tsukina but ofc he isn’t aware of that) and envy towards tsukina and ill being in a relationship when he was clearly developing feelings towards her.
he seems to be under a lot of pressure, both self inflicted and from the public as they’re still looking and are more keen to see the caster of the barrier. he is placing a lot of pressure on himself which is very evident in his actions and behaviour, and i believe that because of this pressure his mental and emotional state will become fatigued and unbalanced causing him to be manipulated.
he’s got a pure and heroic intent but bc of the pressure that is slowly building up it makes him an easy target as he will be in an unstable mindset.
I have a feeling that our new saviors gonna be manipulated somehow and probably because he won't be able to get our FL if he stays in that country or somethn? It might be a story of jealousy to come ٩(๑❛ᴗ❛๑)۶