Xenoblade Chronicles 2 based game

[Zebraoracle]

So I'm trying to build a campaign for some friends drawing heavily from the Xenoblade Chronicles 2 blade system (link below for reference). I have so many different ideas on how to make it work, but putting them together to make something that works and meshes well together is proving difficult. I think I might just have too many ideas that I'm trying to fit into this, but who knows.

The biggest hurdle I'm trying to overcome is working out the blades' abilities. Do I want them to be like a sorcerer's bloodline, where they get a few main abilities and some spells (not actually spells, just an example), or do I want them to have one or two main abilities and then give them a list of smaller abilities they can pick from like the rogue talents? Do I want to give them role options (support, defense, attack) and give them automatic abilities tied to those roles? There's just so much I can do here and right now it feels like none of my ideas mesh well together.

I also decided to just go with a whole new class for this as well, as the setting I'm going for has very low magic (so there wouldn't be wizards, clerics, etc), so I can't just go with "pick your class as normal and here's a thing that adds a couple abilities for you". Then again, I also thought about the blades granting the class, but that would limit the players to casters only since these are magical beings (in this setting).

Any thoughts y'all can throw at me here?

https://xenoblade.fandom.com/wiki/Blade

[aimlessPolymath]

Haven't played Xenoblade but here's my 2c.

First off- it sounds like you have a system in mind for the game, presumably some kind of D&D variant. Do consider the impact of removing large amounts of magic from the game- D&D 3.5 and Pathfinder, in particular, I don't think handle total loss of magic very well at higher levels. Other systems may be more appropriate, depending.

Here are some general thoughts to consider:
-What are the different kinds of PCs that you think you might have playing together? Will all of them have a Blade, or just some of them? Are Blades going to be PCs, or NPCs? (a two-player character would be very interesting, honestly, but might lead to backseat driving)
-What would it mean if someone not suited for a Blade gets one? If, say, a level 2 archer gets a Blade, does that mean they stop using archery because they have a 'stronger' option? Generally, how much does the Blade you get define your character?
-If not everyone has a Blade, how do those without one compensate for this lack? Even via opportunity cost- if you need to spend some character build into Blades, that's a way for the others to compensate.
-There's a big difference between standalone abilities (ex. "fireball, 1/day") and supplemental/passive abilities (ex. "+3 to attack rolls with this weapon") in my opinion- the former is much easier to fit into "generic character X" since they can switch between their basic moveset and the alternate option, while the latter case requires you to be a Blade-user to properly use.
-Do Blades get their own actions? This significantly increases combat complexity.

There are obviously a number of ways you can set up the Blades. In terms of customization complexity, I'd consider them as a part of the base character- if characters can already significantly customize their own character to fill some kind of role, then it's less important to have the Blades fill that gap, and they should be fairly simple. If you need to take "Blade-user" levels and sacrifice the rest of your build, though, then those blade-user levels should provide comparable levels of customization to other classes.

Edit: Checked title, saw Pathfinder. I think Pathfinder is probably one of the better systems for building "generic" customization options in, because it's relatively structured; instead of building your own ability list manually, you can simply borrow a spell list and/or abilities from domains, bloodlines, oracle mysteries, etc to get a Fire blade, a Storm blade, a Death blade, etc.
I'd consider making Blade use integrated into the feat system: you take the "blade-user" feat to unlock access, then "advanced blade-user" and so on to gain further powers.

[Zebraoracle]

Yeah each player would have one.

Each blade offers a selection of weapons, instead of just one weapon like in XC2, so people aren't as restricted.
I'm trying to decide if the blades get their own actions like a summoner's eidolon, or if the player has to choose if their PC or their blade gets an action that turn. For the most part, my group doesn't spend forever deciding on actions so both PC and blade getting actions in theory shouldn't slow things down too much.

[aimlessPolymath]

Yeah each player would have one.

Each blade offers a selection of weapons, instead of just one weapon like in XC2, so people aren't as restricted.
I'm trying to decide if the blades get their own actions like a summoner's eidolon, or if the player has to choose if their PC or their blade gets an action that turn. For the most part, my group doesn't spend forever deciding on actions so both PC and blade getting actions in theory shouldn't slow things down too much.

If each player has a Blade and doesn't pick which one exactly they get, then I'd suggest that they grant some broadly useful abilities (everyone likes spell-like abilities! Not everyone needs +3 to AC equally- melee vs. ranged), probably drawing from a cleric domain or oracle mystery.
If players can pick and choose Blades, then you have more freedom to give abilities that fit more specific character builds; they might emulate specific magic weapon enchantments or grant feats, for example. My personal preference is against making combat roles an explicit part of the system, but you may disagree.

Action split vs. double sets of actions is partly a complexity question, partly a matter of how broad the Blade actions are and how involved they are in combat- if they would only really have one or two options available to them (or actions identical to the abilities they would otherwise grant the PCs), I don't think it's necessary to give them their own set of actions.