"But I was patient. I wrote back. I was sympathetic, I was kind. Ginny simply loved me. No one’s ever understood me like you, Tom …. I’m so glad I’ve got this diary to confide in …. It’s like having a friend I can carry around in my pocket …." (p309, Harry Potter 2, US edition)
NB -- The speaker, Tom Riddle, is a villain in this story. He is boasting how well he could win Ginny’s heart by becoming a kind of pen pal with her.
The author describes his character as an impatient, unsympathetic, and unkind one. Therefore, I would think his saying expresses temporal action, not permanent character. He treated her kindly at that time and his attitudes got Ginny to fall in love.
But I feel something strange when ‘I was kind’ and ‘She loved me’ express action, for I’ve run into much more ‘be kind’ and ‘love’ which describe someone’s character or continuing state since I started studying English.
So, here is my question. Is there any nuance in ‘I was kind’ when it means ‘I treated her kindly”? In other words, why does the speaker use such expressions, instead of other expressions like ‘treat kindly’?