Board Thread:General Discussion/@comment-3030647-20170331102126/@comment-3030647-20170401033113

They're almost like an elite band of Rune Knights, you could say.

Basically, those Rune Knights who have significantly contributed to the Rune Knights' current status, whether it be through training regimes, introduction of new combat principles, branches, etc, are seen as distinguished. If they meet a certain criteria (laid out above) then they are invited to join the Holy Knights.

The Holy Knights perform high-level missions compared to the Rune Knights, taking a more active approach in monitoring and subduing Dark Guilds as opposed to Rune Knights, which monitor the Legal Guilds a bit more.