Blue Spear Monk is an enemy in Sekiro: Shadows Die Twice.
Blue Spear Monk Location
Blue Spear Monk Rewards
Blue Spear Monk Notes & Tips
Although this monk originates from the Misen Temple, and not that of Senpou, they bear a striking resemblance in their character models, although these appear to be more aggressive.
He can be found after fighting the 'White Spear Monk' in the wide clearing to the left of the structure that leads to the Hirata Estate - Main Hall, or after finding Owl for the first time if that's too complicated.
Though they are monks of a temple, they're unaffected by 'Divine Abduction,' reminding the player that these are a group separate from those on Mt. Kongo's Senpou Temple. This also explains why they are one of the only enemies, aside from those at the main hall's entrance in Senpou, that drop Gokan's Sugars.
After the first invasion of Ashina Castle, the Blue Monk next to the Old Grave's Idol will have an eavesdropping opportunity, with him mentioning his worries for Ashina; among other things.
Blue Spear Monk Story & Lore
If Ashina is invaded for the first time by the Interior Ministry
"Hmm...The tides will soon turn against this land."
"I never would've thought the Interior Ministry would become our enemy."
"If the old lord falls...we'll be defeated swiftly, no doubt."
"I'm wondering though, if that happens, will we still get paid?"
"There's no point in running away with an empty purse."
If Ashina is invaded for the second time by the Interior Ministry
([Buddhist Chanting] Namu Amida Butsu, Namu Amida Butsu...)
... Everyone.. Forgive me.
But nobody would put their life on the line for free...
All right, so... how do I make my escape... ?
- The Shinobi Hunters are Misen monks, people who have trained their body and core to an extreme level in order to properly combat Shinobi, as properly represented when they drop Gokan's Sugar, which boosts their core (posture).