I'm not sure specifically as I haven't read it in detail. But generally, a 'poison healer' in a light novel might be about a character who uses poison in an unconventional way for healing purposes, perhaps with a unique magic system or set of skills related to it.
It's a story about a healer who gets the chance to redo his life. He uses his new - found knowledge and power to take revenge on those who wronged him in his previous life.
One characteristic is the focus on the power of healing. The healer characters often have to deal with various wounds and diseases in the story. For example, in many healer light novels, they can use magic or special skills to cure the sick or injured.
Typically, the protagonist in an 'e rank healer light novel' is initially seen as weak due to their low rank. However, they often have a strong will. For example, they might be determined to improve their rank in the healer's guild or gain more respect from their peers.
I'm not entirely sure as I haven't read it in detail. But generally, a light novel often features a unique story world, interesting characters, and a plot that may involve the journey or adventure of the healer in the title. Maybe it's about the healer achieving complete liberation (kanzen kaiho) and creating some sort of miracle (kiseki).
It's a series that involves a protagonist with the ability to redo time. He uses this power to take revenge on those who wronged him in the past. The story is filled with action, adventure, and some dark themes as he navigates through a world full of magic and power struggles.
One common plot element is the search for an antidote. When poison is involved, the healer is usually on a quest to find the right ingredients and spells to counteract it. This often involves exploring the Forbidden Forest or delving into ancient potion books.