Butcher is a star within the Constellation The Atronach in Elder Scrolls Online.
This was added in Update 6 with the Champion System. Light and Heavy Attacks deal 5% extra damage to targets below 25%. 75 points in the Atronach Constellation are required to unlock it.
The Passive bonus is not applied account wide on all characters, it applies only the character that unlocked the passive with champion points, I have already tested this and can confirm that the above information is "Once unlocked the player will acquire this bonus automatically and across all characters on their account. ", is misleading and inaccurate.Please edit the information to show the actual application of the Champion Passives.