The Kardashian sisters are allegedly back to hating Blac Chyna as, according to reports, they believe she is emotionally abusive to their brother, Rob, and they're working at putting a stop to it for good.

In Touch reports that they have heard "so many bad things" about Chyna, including her alleged emotionally abusive ways towards their brother and even infidelity.

"They believe his fiancé, Blac Chyna, has been psychologically abusive to Rob," a source told the publication. "At first, they thought she was a positive influence, but they now believe she is killing him. So, after Rob's emergency trip to the hospital, his family hatched a plan to get rid of Chyna once and for all."

The Kardahian matriarch, Kris Jenner, apparently is spearheading the plan as she has reportedly hired a private investigator to find out exactly what Chyna's been up to.

"The family is writing everything down and will present it to him," the source added. "They will sit him down for an intervention and place an envelope containing all the proof of what she has done on the table in front of him. They want to have a psychologist on hand so they can discuss how Chyna abuses him."

Chyna's reported emotional abuse at Rob's expense is no secret. She's known to tease him about his weight by calling him "fat, lazy and insecure" in private text messages that were leaked when her phone was hacked.

For more on Rob and Blac Chyna, check out the BET video above.