What does Kogarasumaru do in CK3?

Prowess +2, Prestige +0.2/month, Natural Dread +15 (patch 1.20.0.3).

How do you get Kogarasumaru with the console?

effect create_artifact_kogarasumaru_sword_effect = { OWNER = root } — runs the scripted effect that makes it, for the character you play (debug mode).

Personal artifact · Weapon

Kogarasumaru

Famed

Kogarasumaru is a famed weapon artifact in Crusader Kings III: Prowess +2, Prestige +0.2/month, Natural Dread +15. Quality 70 and wealth 70; maximum durability 100, and it does not wear out. Made on 940.1.1 for Yuta'akira Yamato in Heian-kyō. At game start it goes to the holder of Kanmu Family (starts from 1066.9.15). Patch 1.20.0.3, from game/common/scripted_effects/01_exp1_historical_artifacts_creation_effect.txt.

Quick answers (2)

What does Kogarasumaru do in CK3?: Prowess +2, Prestige +0.2/month, Natural Dread +15 (patch 1.20.0.3).
How do you get Kogarasumaru with the console?: effect create_artifact_kogarasumaru_sword_effect = { OWNER = root } — runs the scripted effect that makes it, for the character you play (debug mode).

The 'Little Crow' was forged by Amakuni for the imperial court, and later bestowed upon Taira Sadamori by Suzaku Ten'nō for service in the Jōhei-Tengyō rebellion.

Effects

History and who has it

Made on 940.1.1 for Yuta'akira Yamato in Heian-kyō.
At game start: the holder of Kanmu Family (starts from 1066.9.15).

How it is made

The game creates it with the scripted effect create_artifact_kogarasumaru_sword_effect. In the console (how to open it), this gives it to the character you play:

effect create_artifact_kogarasumaru_sword_effect = { OWNER = root }

Built from the effect's file; not run in the game by us.

Source: game/common/scripted_effects/01_exp1_historical_artifacts_creation_effect.txt, common/modifiers (kogarasumaru_sword_modifier) and the English localisation, Crusader Kings III 1.20.0.3.