Two of the most senior members of the Rebels bikie gang in Darwin have pleaded guilty to offences that left a man, who was not the intended target, with serious injuries and psychological damage.

The Rebels outlaw motorcycle gang's sergeant of arms Shannon Atlhouse and president Andrew Summerfield ordered the attack, the NT Supreme Court heard.

The pair pleaded guilty to recklessly endangering serious harm and unlawful entry to a house with intent to assault while armed.

The court heard the men planned an assault of Tyrone Kerslake in October 2016 after he allegedly injured Althouse weeks earlier.

Althouse and Summerfield had been to several shops earlier in the day and purchased hatchets, machetes and balaclavas.

"As the senior office holders of the Rebels, Summerfield and Althouse instructed [the] persons to carry out the assault upon Kerslake," a statement of facts read.

"These persons took possession of the weapons and balaclavas that the offenders had purchased."

The armed men then went to Mr Kerslake's house but he was not home. His housemate Bradley Jewell was there sitting in his living room watching television.

The court heard the men attacked Mr Jewell, striking him to the head and neck with hatchets, before fleeing the scene.

Mr Jewell suffered a severed vertebrae, brain injuries, a fractured skull and had his fingers nearly cut off.

Three days later Summerfield and Althouse were arrested.

Forensic analysis of one of the axes found at Summerfield's house revealed Summerfield's DNA on the handle and blood with DNA matching the victim on the blade, the statement of facts said.

In consequence to the attack, Mr Jewell said he continues to suffer significant physical and emotional disabilities, fears reprisals and is scared to leave his house.

Both men will be sentenced next month.