How does Roger Chillingworth interact with others throughout the novel The Scarlet Letter?

According to Hawthorne's narrator,had all his
life been kind, though not warmly affectionate, and calm in temperament. He had spent his life
as a scholar in solitary pursuit of knowledge, which is what led him to desire 's warming
companionship to begin with, as he still cherished the hope of discovering the joys of love and
affection, even though his scholarly pursuits still occupied him. The narrator clearly states
that Chillingworth had always been "pure and upright" in his interactions with
others.

However, as a direct result of the consequences of the Minister's and
Hester's impropriety and indiscretion, Chillingworth underwent a great change of nature. He was
"seized" by a "fierce" and terrible "fascination" that propelled
him down a new path on which he was not free to follow anything but the fascination that gripped
him. He fell from his pure and upright standing because of bitter disquietude over the wrongs
inflicted on him that robbed him of what he believed was his one chance at the attainment of
love and a warm affectionate heart.

After this fall, after having his worth
chilled by the icy grip that seized him, Chillingworth became a "leech" of others'
worth drained from their souls just like he would leech the goodness from the herbs in his
medicinal studies. Those herbals were meant to be used for good, but the leeching of others'
souls was meant for harm. Though his interactions with others were pure and upright at the
start, even if preoccupied and cool, his interactions at the end were devious, manipulative,
insinuating and harmful.