So i was creating a replica of the Acheron Blade, and i was wondering how to make it possible to be based on any sword as the spell says, or if I need to make a copy for each sword, how to add actions if that is possible, or ill just leave it up to the players to use it properly.

Even the official “Any Sword” options are created individually for each sword, and then one additional time to add the “Any Sword” version as per RAW.

The “any sword” version is not strictly necessary for homebrews, you could skip that if you didn’t want to make the extra version.

PS- Take the space out from in between “magic” and “item” so it reads “magicitem” and your tooltips will work like this: acheron blade.

Quote from IamSposta >>

Even the official “Any Sword” options are created individually for each sword, and then one additional time to add the “Any Sword” version as per RAW.

The “any sword” version is not strictly necessary for homebrews, you could skip that if you didn’t want to make the extra version.

PS- Take the space out from in between “magic” and “item” so it reads “magicitem” and your tooltips will work like this: acheron blade.

 Thanks for the help, but then how would I be able to add the actions like:

Dark Blessing. While holding the sword, you can use an action to give yourself 1d4 + 4 temporary hit points. This property can't be used again until the next dusk.

Disheartening Strike. When you hit a creature with an attack using this weapon, you can fill the target with unsettling dread: the target has disadvantage on the next saving throw it makes before the end of your next turn. The creature ignores this effect if it's immune to the frightened condition. Once you use this property, you can't do so again until the next dusk.

Actions cannot be added to magic items at this time. They’re just done with plain text.