The eldritch revelation and eldritch ephany are (afaik) the only two unlocks that have a required level of warp. Everything else is obtained via scanning and/or reading the Crimson Rites book.
You don't seem to have read the Crimson rites. To get it you need to search the world for eldritch obelisks with cultists, carefully draw off the knights and kill loads and loads (and loads and loads) of them while not aggroing the Crimson Clerics. Once aggro'd the clerics will attack you and even if you run away they will NOT resume channeling dark energies into the central sinister node. Clerics that are not channeling will despawn as per the regular hostile mob despawn rules, and a eldritch obelisk without clerics will not spawn any more clerics or knights and thus becomes, essentially, useless for the purpose of finding a copy of the Crimson Rites.
If you have any mods that allow you to capture mobs and create spawners (EIO) do so - capture at least one Knight and Cleric, and run them in a powered mob grinder until the book drops - plus they drop crimson armor that looks neat on armor stands, and void metal nuggets.