pure, unmixed, genuine / selfless, pure / innocent

purity / selflessness, purity / innocence

action; behavior

to act

brutal; tyrannical

brutality; tyranny

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend

(と〜) thinking that […] (with the next clause explaining that the truth is contrary to expectations)