IMO, if you want to stay on a level cap (say, 100, 120) is better to not touch Skill for a Chikage build.
The most damaging attacks comes from the blood side, and it was differentiates the weapon to the other skill weapons, cause the blood mode is more damaging even the regular R2s, let alone the sheathe animation.
Of course, if you don't care about a level cap you can level both BLT and SKL to 50 and use both modes of the weapons, although honestly I don't see much point, It's all about the starting L1 to R1 Thanks god the Chikage doesn't require both, unlike the Moonlight sword, that requires a crap ton of stats to use it.
edit: and of course, don't do like me right now and don't write a post while you leave your character with the Chikage in Blood mode lol
The most damaging attacks comes from the blood side, and it was differentiates the weapon to the other skill weapons, cause the blood mode is more damaging even the regular R2s, let alone the sheathe animation.
Of course, if you don't care about a level cap you can level both BLT and SKL to 50 and use both modes of the weapons, although honestly I don't see much point, It's all about the starting L1 to R1 Thanks god the Chikage doesn't require both, unlike the Moonlight sword, that requires a crap ton of stats to use it.
edit: and of course, don't do like me right now and don't write a post while you leave your character with the Chikage in Blood mode lol