Cryptex | Artifact | | {T}, Collect evidence 3: Add one mana of any color. Put an unlock counter on Cryptex. (To collect evidence 3, exile cards with total mana value 3 or greater from your graveyard.)
Sacrifice Cryptex: Surveil 3, then draw three cards. Activate only if Cryptex has five or more unlock counters on it. | Yeong-Hao Han
LSV
Gravestone Strider | Artifact Creature | Golem | {1}: Add one mana of any color. Activate only once each turn.
{2}, Exile Gravestone Strider from your graveyard: Exile target card from a graveyard. | Tom Babbey
2.5 LSV
Sanitation Automaton | Artifact Creature | Construct | When Sanitation Automaton enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.) | Mike Burns
1.5 LSV