Tang Yanran did not think her poisonous body had any immunity to her own family's medicines. Since she was a child, she had been soaked in medicinal concoctions, and thus believed her family's drugs would not harm her.
However, after she consumed the detoxifying Vitality Pill, the poison in her body was removed. Not only that, but all the toxic impurities in her system were also cleared away.
This turned her into someone who used poison, but was not a poisonous person herself.
Jiang Tang was rather tolerant of the women around him. Take Tang Yanran for instance, the daughter of the Tang Family, a woman skilled in using poisons, who had once tried to deal with him underhandedly. For a woman who failed to succeed in her schemes, he only had leniency.
How could he blame such a beauty for liking him?
He was also aware that it was for the sake of benefits—even so, it didn't matter. He wasn't a saint; if not for benefits, he wouldn't be working so hard himself!