Relics
How to fill three relic slots
Three jobs, not a ladder
There is no tested ranking of all 42 relics. The useful split is the three slots you actually have. A damage slot can be Obsidian Fang, Twilight Gem, Sinister Rune, or Necro Charm, because those are the quoted damage effects. A survival slot can be Shadow Veil, Midnight Tear, or Witch's Knot. A utility slot can be Crypt Key, Mourning Bead, or Lich's Mark.
Attack and defense on the equipment screen are not only relics. Levels and the red and blue books move the same numbers. A relic build that ignores books will look weak for reasons that are not the relic.
What I will not call the best
Family's Grace has no published effect, so it cannot be ranked. Eyes you equip to open the Gate of Flesh are keys, not a combat build. Swap them before Mammon. A future timed test would be labeled with the weapon, the level, and the room. That test is not this page.
What I ran into
I wanted a single 'equip these three' sentence. It would have been my taste, not a measurement. The page gives the three jobs and the relics that match them, and it stops before a crown.
Questions
What are the best relics?
No complete test exists in the sources. Match a quoted damage effect, a quoted survival effect, and a quoted utility effect to your three slots.
Do relics replace leveling?
No. Levels and the red and blue books also change attack and defense.