The Shovel Of Alden's lore in this campaign setting is that it is a magical shovel associated with someone named Alden, in the distant past. Alden, who nobody has seen in recent memory, apparently still has a bunch of followers acting on his before, commonly referred to as The Cult Of Alden. The shovel went missing long ago somewhere in the Goldvale area and the cult members are constantly trying to reacquire it because it is a powerful weapon with vampiric properties. The campaign has seen Cult Of Alden members frequently fail at this task.
The lore most know about the Shovel Of Alden is that its influence overwhelms any single person who carries it for more than a day straight. Historically, Alden had been “heavily influenced” by it and he created a team of 3 goblins whom carried the shovel when he was not in possession of it, passing it amongst themselves to prevent anyone else from being corrupted. These three shovel bearers were represented by wearing tunics with a white triangle on it, representing their place as The Three1).
The lore only a few higher ups in The Cult Of Alden know about the Shovel Of Alden is that the influence or “corruption” it causes to someone who holds onto it for too long actually causes them to start to become what might be known as “Alden Reborn”. They begin to change, and the details are murky and lost to Time from there. This is the true reason members of the cult are sent to seek the shovel, in the hopes of bringing back their leader to the world.
The Shovel Of Alden traces back to a game I ran in an online format on a forum, long ago, while working a boring office job. A coworker joined the game with a character named Alden, a goodly paladin, initially. I introduced an evil god that wanted to corrupt his character, and for reasons I forget now, a shovel became Alden's weapon of choice for smiting things. The evil god, known as Hayte, eventually bestowed a vampiric power on the shovel so that attacking with it did some decent damage and also stole hit points from the target and gave them to Alden, buffing him up.
Later, that game long past, in yet another campaign, I'd reintroduce the “Shovel Of Alden” as a cursed shovel weapon that does vampiric damage and ultimately works to corrupt the PC that has it. It's pretty hard for a player to resist running around with a shovel that actually heals them and lets them beat the snot out of things, so I deemed this fun enough to keep returning to.