This homebrew mod introduces several enhancements for the bladebound magus sub-class archetype, focusing on the summoned black blade scimitar. Key changes include:

• Enhanced Black Blade: Grants a +1 bonus to Base Attack Bonus (BAB), allows melee attacks and damage rolls to use the higher of STR or DEX bonuses, and upgrades the black blade scimitar to a D8 damage die (instead of D6). These benefits apply only when the black blade is equipped.
• Customized Spellbook: Adds additional spells, including most 1st to 6th level wizard conjuration spells, and enables some 7th to 9th level wizard spells but at a slower progression compared to a wizard. It is not currently enabled to merge with Lich or Angel spellbooks. 
• New Level 16 Ability: The Bane of the Black Blade ability increases the black blade's critical hit multiplier for 1 arcane point per minute.
• Bladebound Greater Spell Access: Allows selection of up to 9th level spells, replacing the magus Greater Spell Access feature.
• Exclusive Background: The Dark Pacts background increases the duration of summons, similar to the Conjuration wizard specialist school. Only selectable by the bladebound.
• Bladebound Proficiency: Grants Weapon Proficiency (Scimitar) and Light Armor feats, while removing Simple and Martial Weapons proficiencies due to the bladebound's focus on the black blade.
• Life Drinker Enhancement: As of 1.0.5 of this mod, the black blade Life Drinker feature now provides a benefit for any foe slain, not just those whose Hit Dice are greater than or equal to half the bladebound's level; and, unlike the base game, it also now shows a status icon while it is providing temporary hit points (with the time remaining displayed). These temporary hit points will last for 1 to 10 minutes (instead of just 1 minute) for slaying a foe that has Hit Dice equal to or greater than half the bladebound's level; but, if the foe's Hit Dice are less than half the bladebound's level, the temporary hit points only last for 2 to 4 rounds. As with the base game, slaying an enemy while Life Drinker temporary hit points are already in affect will restore 1 arcane pool point. I feel that this change makes Life Drinker an archetype-defining capability, driving a dynamic and exciting play style...consuming the souls of your foes provides protection and regenerates your arcane pool...driving other abilities, spell recall, etc. The base game ability was good, but I felt it needed a bump.
  

In totality, I think that these changes make the bladebound a more specialized and powerful subclass, with abilities centered around the unique black blade.

In order to use this mod, you will need to have the Pathfinder Wrath of the Righteous: A Dance of Masks DLC, as I don't believe that the bladebound archetype is available without it (I have the DLC so can't confirm). 

This mod is compatible with the latest versions of the game (v.2.5.0aa, v2.5.0y and v2.4.1i).   

Installation Instructions

Note: This mod is an Owlcat Wrath Modification Template-based mod, not a Unity/C# mod. As a result, you cannot install it with Unity Mod Manager because, unfortunately, Unity Mod Manager does not install mods built via Wrath Modification Template. While tempting, I decided not to dust off my Fortran and Pascal programming skills from college from 35 years ago to learn C#. Instead, the mod was created using a combination of Owlcat Wrath Modification blueprint patching and inserting new blueprints. I've been tinkering with C# so I may overhaul the mod to C# someday; but, for now, here are the available installation methods:

Option 1: ModFinder (easiest)

1. If you don't already have ModFinder by WittleWolfie, download it from here: ModFinder on GitHub and ensure you have the prerequisites for it installed (Unity Mod Manager, .NET Desktop Runtime 5.0...both linked from the ModFinder GitHub page)
2. Download this mod (i.e. The Black Blade) from the Files tab of this mod
3. Launch ModFinder
4. Drag and drop this downloaded mod's zip folder to the "Drag zips here to install" area at the bottom of the ModFinder interface
5. Sort columns in ModFinder by clicking on "Status" and ensure that you see "The Black Blade" listed, and the status is "On"
6. Launch Pathfinder Wrath of the Righteous and enjoy your new and improved bladebound archetype

Note: I personally like ModFinder for managing my Wrath mods better than Unity Mod Manager because ModFinder manages both Unity/C#-based mods and Wrath Modification Template-based mods. For various reasons, it seems that ModFinder is not being updated on Nexus anymore. If you want to use it, you need to download the latest version from GitHub, as linked above.

Option 2: Manual (still easy, you just need to be very detail-oriented and a little proficient with a text editor like Notepad or similar tool)

1. Launch Windows Explorer
2. In Windows Explorer, turn on View > Show > Hidden Items (on Windows 11, earlier versions of Windows may be slightly different, but you need to enable viewing of hidden files and folders)
3. In Windows Explorer, navigate to C:\Users\<your profile directory>\AppData\LocalLow\Owlcat Games\Pathfinder Wrath Of The Righteous
4. If you don't already have a folder called Modifications in this directory, please create it
5. Download this mod (i.e. The Black Blade) from the Files tab of this mod
6. Unzip this mod and copy TheBlackBlade folder and all subfolders/files to the Modifications directory above
7. If you don't already have a file called "OwlcatModificationManagerSettings.json" in your C:\Users\<your profile directory>\AppData\LocalLow\Owlcat Games\Pathfinder Wrath Of The Righteous folder, create it (make sure that the text file you create has a .json extension, not .txt)
8. Use your preferred text file editor to open your new "OwlcatModificationManagerSettings.json" file and edit it to look exactly like this (save the file after adding this content):

{
  "EnabledModifications": [
    "TheBlackBlade"
  ]
}

8a. If you have other Owlcat Wrath Modification Template-based mods already installed, you will see other mods listed in your existing OwlcatModificationManagerSettings.json file. In that case, just add "TheBlackBlade" (pay special attention to ensuring you have the correct syntax utilizing quotation marks, commas, and brackets) to the list of mods. In this case, your OwlcatModificationManagerSettings.json file would look something like this when you are done (remember to save the file after editing):

{
  "EnabledModifications": [
    "OtherMod1", "OtherMod2", "TheBlackBlade"
  ]
}

9. Launch Pathfinder Wrath of the Righteous and enjoy your new and improved bladebound archetype

Optional Portrait

The portrait used in my screenshots is included as an optional download. Credit for this amazing artwork goes to Gerald Brom, one of my favorite fantasy artists. His haunting and iconic imagery captured my imagination as a young adult, and the artwork used for this portrait perfectly matched how my imagination pictured one of the most influential fantasy characters of all time, my favorite albino anti-hero and his soul-devouring sword.

Future Enhancements

I'm thinking of several additions for future versions of the mod (feel free to let me know your thoughts on these or other ideas in the Comments):

• (Unlikely) Require the Manifestation of the Black Blade to consume scaling arcane pool points to reflect the blade's growing hunger and drain on the bearer. Of course, drinking the souls of enemies satiates the blade and restores the bladebound's pool...the symbiotic relationship of blade and bladebound. The more I think on this, the more it is just an annoyance, unless I give the summoned black blade a duration where you'll need to be careful to retain some arcane pool to summon the blade regularly, or you'll need to rest to regain points and be able to call the blade...otherwise, just don't ever unequip it and this is a pointless debuff. Low priority concept...I probably won't implement this unless feedback shows people really like the idea.
• (Maybe) At upper levels, a feature to represent the blade's unquenchable hunger and increasing ego causing the bladebound to lose control and attack any nearby target. Perhaps adding it to the Bane of the Black Blade ability and creating a requirement to pass a Will saving throw every x number of rounds during combat or your character attacks the nearest creature until you pass another Will saving throw each round. I do like this as a balancing factor, but not sure yet how hard it will be to implement without resorting to writing C# code.
• (Likely) Instead of my earlier idea listed here of having an ability where the bladebound can cast Fear through the blade once a day, or something similar, I think I will morph this idea into an effect similar to the Hellknight Signifer's "Order of the Scourge" feature. Once the bladebound gets Life Drinker and starts consuming the souls of those slain with the black blade, these horrific death screams lower the Will saving throws of nearby enemies.
• (Conceptualizing) Add some additional features that the bladebound can spend arcane pool points on. I'm inclined for this to be limited duration buffs...saving throws, stat points, etc. With the buff of Life Drinker, the bladebound will have a steady stream of arcane pool points coming in...I can see most going to existing abilities, especially spell recall for upper-level spells, but anything to create difficult or impactful choices for the player is a good thing...keeps things interesting.
  

As noted, this mod is created with Owlcat Wrath Modification Template and that limits to a degree what I can do to realize any of the above ideas.

Thank You

For any who try out the mod, thank you! I hope you like it and always happy to hear your thoughts in the Comments...especially if you find any bugs!