Has the Cult Leader Cleared His Name Yet?

Ten years ago, the leader of the Demon Cult, Lan Yue, and Wen Miaohe, the master of Hengjian Manor, secretly conceived a child, Wen Sili. He grew into a wicked son who slaughtered righteous martial artists and threw the whole martial world into chaos. The Myriad Alliance joined forces with various sects to destroy the Demon Cult, and Lan Yue and Wen Miaohe both died in the battle...

Ten years later, Wen Sili, the sole survivor, became the new leader of the Demon Cult and returned to take revenge. The martial world was plunged into turmoil once more.

Sects were wiped out, young women had their hearts cut out, and every bizarre incident in the martial world ultimately pointed to the Demon Cult.

Meanwhile, Shen Fengling, who had joined Hengjian Manor, encountered a boy named Shen Langxing during a trip down the mountain. He had saved the boy years ago. Now grown into a graceful young man, Shen Langxing was aloof and noble to everyone else, but gentle and always willing to do anything Shen Fengling asked.

Just then, Shen Fengling was framed and expelled from Hengjian Manor. With no other choice, he set off for Shaolin with Shen Langxing.

Until one day...

His childhood friend and first love, his senior apprentice sister, warned him, "Be careful of Shen Langxing. He's the Demon Cult leader who framed you!"

Shen Fengling: "???"

Beautiful, scheming Demon Cult leader x steady swordsman

PS:

1. The leader has been poisoned with a strange toxin. When it flares up, a pattern of the flowers of the other shore appears on his chest.

2. The story features a yandere-type character.

4. The leader is here to repay the male lead's kindness. He won't hurt him.

3. The road ahead is long and arduous, but the Demon Cult's redemption is in sight.

I spent ages trying to think of a fitting title. This one should be the best fit so far.

Theme: To stand up for the weak and fight injustice, you must first be strong yourself!