Amulet of the Pit Lord

 is a passive item.

Effects

 * Falling into pits no longer deals damage.

Synergies

 * If the player also has Blue Guon Stone, the rotation speed of the Guon Stone is increased but it orbits farther from the player. If the Guon Stone blocks a bullet, it deals 15 damage to all nearby enemies.
 * If the player also has Clear Guon Stone, it grants immunity to poison, fire, and electricity. Shooting enemies while standing on fire or ice will burn or freeze them, respectively.
 * If the player also has Flare Gun, it turns green and sets green fire, which doesn't hurt the player and leaves non-boss enemies permanently burning.
 * If the player also has Green Guon Stone, the stone's chance to heal the player is raised to 70% if the player is one hit from dying and 20 also appears whenever Green Guon Stone heals the player.
 * If the player also has Orange Guon Stone, it shoots twice as fast and deals 8 damage rather than 5.
 * If the player also has Pink Guon Stone, enemies that damage the player become temporarily charmed.
 * If the player also has Red Guon Stone, the player gains a yellow glow and stat increase similar to that of the Macho Brace for a short time whenever the Guon Stone blocks a bullet.
 * If the player also has White Guon Stone, Daruma's recharge is halved. However, Daruma itself is not part of the synergy.
 * In addition to their unique effects all -er Guon Stone synergies increase the size of the Guon Stone and make it rotate at a fixed distance from the player while they are moving instead of on a slight delay.

Trivia

 * The item is a reference to a famous Magic the Gathering card "Lord of the Pit." The "bargain" referred to in this text refers to the card mechanic whereby you must sacrifice your other creatures to it or it will harm you.  It is also connected to the unlock method, the implication being that knocking enemies into the pits is sending them to the Pit Lord to be consumed.
 * The code for Amulet of the Pit Lord is stored in a class called 'RingOfPitFriendship', which may have been an in-development name/theme for the item.