Carries a hint of suspicion:
诡 guǐ ('crafty / deceitful') colors
秘 mì ('secret') so the secrecy feels untrustworthy, not just private. Compare
神秘 shénmì 'mysterious' (neutral, even attractive) with
诡秘 'shady, suspect'. Famous in modern web-novel title 《
诡秘之主》 (Lord of the Mysteries).