One relic is required for the research of Antimatter and Tachyon Theory in the science menu, and Cryptotheology requires five.
Researching Cryptotheology
Researching Antimatter
Researching Tachyon Theory
Researching Quantum Cryptography
Purchasing the Chronoforge upgrade
Purchasing the Black Obelisk insight
Purchasing the Black Nexus insight
Purchasing the Black Core insight
Purchasing the Event Horizon insight
Purchasing the Blazar insight
Purchasing the Dark Nova insight
Purchasing the Holy Genocide insight
Building the HR Harvester
Building the Entanglement Station
Building the Chrono Furnace
Building the Temporal Accelerator
Building the Time Impedance
Building the Void Resonator