How to obtain Enigma, Evanescence, Incantation and Skeletar Chests

Visit High Priest - Ganon NPC in Shaitan City at 861,3501 and click on the Research Runestone Option.

Enigma Chests:

You must give High Priest 10 Ter Runestones and 10 Fa Runestones

Evanescence Chests:

You must give High Priest 10 Ja Runestones and 10 Tef Runestones

Incantation Chests:

You must give High Priest 10 El Runestones and 10 Cam Runestones

Skeletar Chests:

You must give High Priest 10 NalRunestones and 10 Sol Runestones

Runestones are farmed in Demonic World, Dark Swamp and Forsaken City monsters.