When used on an Amulet of Glory, the Sinister Scroll would create the Sinister Amulet, a brand new tradeable necklace.
Sinister Amulet provides the same stats as an Amulet associated with Glory, with the added ability of growing the effectiveness of the Smite prayer. Instead of cutting your opponent's prayer by 1/4 of harm dealt, Smite would instead drain by 1/3 of harm dealt.
This product would become untradeable once used and would crumble in order to dust after being worn for 100 hits. We'd like to gather more feedback about how many hits appears to be effective enough without having making the item final for too long.
This particular idea was originally polled back in 2014 with the OSRS Gold for Sale release associated with Bounty Hunter. It achieved around a 72% "Yes" with around 30 thousand ballots.