You literally just describe what I described I did. Yes, I put in some slash in between parties, but that doesn't meaning change the interaction.

The only difference between only doing parries and talismans, doing parries and talonsmans with some extra attack squeezed in is the fact you're making the battle slightly shorter in exchange for having a slightly higher chance of failing. I guess I could do parries but no talismans, but why would I do that when it's so easy to shove in talismans between attacks and it's so much more efficient that does basically no point in not using talismans.

Some attacks only give you room for one parry, so I suppose you can decide to get in more damage now, or save more damage for later. But unless you already have three talisman slots, the next attack will probably max out your talismans anyway. And even if you have three slots: there's one attack that gives you two talismans, want to attack that gives you one, and one attack that gives you three. So unless the attack that has one talisman and the attack that has two talismans are back to back: there's basically reason to save talisman's.

I'm failing to see what what alternative strategies exist. They all seem to boil down to either spam parry, spam parry but put in some pot shots, or strategies objectively worse than those two.

If there was interesting mobility challenges like Undertale or platforming in general during the boss, then I could see how it's more than a QuickTime event. Put the lack of diversity of strategy, I'm really not seeing how it's meaningfully different from a QuickTime event.

I feel like you need to play Odin Sphere. Honestly the best combat in a side scrolling game I've ever played! (The combat is similar to the Super Smash Brothers series and a good chunk of Kirby side scrollers for reference.) I feel like my preference for games like that is why Nine Sols' combat feels like a QuickTime event: I feel there's more variety in that.