I really like this game and I really like guardian spirit skills. Finally we can use our guardian spirits the way other bosses in the series have done. But, in this aspect specifically I really think it should change.
In Nioh 2 you have 73 soul cores which lead to an extremely large amount of combinations.
In Nioh 3 Guardian spirit skills take 4 of the soul core spots and they always are taken in pairs.
Cast time, damage, ailment buildup, and strength are not all created equal between spirits.
The vast majority of them do not play nice with Spirit Ascension because that's based on hit count
For lore, Takechiyo already access the skills of multiple guardian spirits different than exclusively what's being used and we use them all the time for traversal.
For balance, Onmyo builds already have dramatically higher damage and limitless confusion buildup.
Or hey, failing that, somehow add the ability to swap between two guardian spirits per style. What do you guys think?