[Miller]

I think basic would be substantially better but the stats on these weapons also needs to be at least on par with bare fists with trained fist; they don't do a whole lot of damage even when fully built for. Scaling shifting depending on the youkai would be cool too admittedly, but it'd be a bit less intuitive than just slapping on basic and calling it a day compared to having to factcheck each of the weapons for specific scaling.

That said, I could go either way when it comes to scaling; this move has been wholly underpowered since release besides a few resistance shredding niches that were hardly used.

[TorientalVortX]

Couldn't agree more honestly, hence why I think with this change in scaling, that maybe the tiers of levels in shift strike could increase the stats of the weapons power, accuracy, etc similar to upgrading normal weapons and like how it also provides a crit bonus itself currently. More investment for higher return.

[Autumn]

I can side with basic scaling and some base stat adjustments to match upgraded weapons of a similar type. (probably about 15-20 more hit/crit to each weapon would suffice)

[renowner]

Personally I think shift strike should just be entirely reworked into a basic attack type skill.
It can do damage based on the currently installed youkai, with a small boost to crit.
Designed to combo around with bloody shift.

That'd make it a bit similar to ritual sword in bonder, only with a crit boost instead of a fp drain, and the added benefit of changing its damage type.

I don't think it needs to be so convoluted. Most of the information on shift strike isn't even listed in the game, and can easily become a newbie trap.