So, for context: I have it in mind to make a character who will be the guardian of a sacred sword. The story is that the sword was believed to be that of a god and that it has been passed down for generations, being passed on only when the previous owner was dying and being passed to whoever was worthiest (though likely also whoever was convenient). My character will be the latest guardian of the sword, so will start at low level, not really knowing how to use the sword properly. As they level up, they would gain more abilities from the sword - probably in the form of spells.

The keeper of the sword carries it everywhere and is unlikely to use other weapons, so it needs to be a good enough weapon to avoid being broken or melted in pitched battle!

Is there already a sub-class which suits this general idea? If not, I am currently undecided as to which class will best match the sentiment behind the idea, if I can get the DM to agree to my character having a sword which itself grows in power (so I don't get left behind if people get magical weapons). My first thought was a fighter, but now I'm thinking a Paladin could be the way to go, with the whole oath thing binding them to the sword, and presumably to the path of the god whose sword it supposedly is.

I'd really appreciate peoples thoughts on this!

You basically just described hexablade warlock. But kensai monk might give you some options for your own magic weapons

Quote from Huwmen >>

You basically just described hexablade warlock. But kensai monk might give you some options for your own magic weapons

 I haven't got Xanathars guide yet, so had to do some googling! it looks kind of similar - more like a dark version of what I had in mind! I was thinking more of a holy weapon of which my character would merely be the keeper - more smiting and burning wrath rather than summoning the dead and cursing people!

Maybe Eldritch knight? They have the weapon bond and Eldritch strike features. The rest of the abilities is quite generic though.

Kensai was going to be my pitch too. You could reskin one of the paladin oaths to fit your needs, alternately there is Celestial warlock with the pact of the blade. The only other weapon specific subclass I can think of is blade singer wizard (swords coast adventure guide and reprinted in Tasha's)

A paladin could work pretty well for this, possibly an Oath of Conquest paladin.

If Hexblade doesn't fit then any Paladin or Cleric would do.

For the weapon you'll want to talk to your DM about making something like a Vestige of Divergence from Exandria - essentially an item that improves itself over time based on the acts of the person wielding it.

If you pick a spellcasting class it becomes quite easy to simply say every other new spell acquired is granted by the sword rather than a class feature, for instance, but something similar can be done with just about any and all class abilities. An Eldritch Knight's entire spellcasting ability could be reskinned as being granted by a sword (which would help explain that ability only kicking in at lvl 3 as well), a Paladin's Smite or Channel Divinity features could originate from the sword rather than his oath, a Barbarian's Rage could be induced by the weapon instead of being an internal thing, and so on. The sword itself can be improved through rituals or quests or prayer or whatever you or the DM feels is more appropriate. Your character finding or buying a better weapon is functionally no different than your character finding his weapon has unlocked a new power or deliberately unlocking it himself, after all.

Essentially, you don't have to create anything new for this - just reimagine existing mechanics as a function of the blade rather than your class and agree with your DM that whenever you'd have a chance to acquire a better weapon during the campaign this gets reskinned as your sword becoming stronger. You'd only be changing the aesthetics of your character, nothing mechanical, so no need to homebrew or worry about balance.

I suggest homebrew.

Quote from pangurjan >>

If you pick a spellcasting class it becomes quite easy to simply say every other new spell acquired is granted by the sword rather than a class feature, for instance, but something similar can be done with just about any and all class abilities. An Eldritch Knight's entire spellcasting ability could be reskinned as being granted by a sword (which would help explain that ability only kicking in at lvl 3 as well), a Paladin's Smite or Channel Divinity features could originate from the sword rather than his oath, a Barbarian's Rage could be induced by the weapon instead of being an internal thing, and so on. The sword itself can be improved through rituals or quests or prayer or whatever you or the DM feels is more appropriate. Your character finding or buying a better weapon is functionally no different than your character finding his weapon has unlocked a new power or deliberately unlocking it himself, after all.

Essentially, you don't have to create anything new for this - just reimagine existing mechanics as a function of the blade rather than your class and agree with your DM that whenever you'd have a chance to acquire a better weapon during the campaign this gets reskinned as your sword becoming stronger. You'd only be changing the aesthetics of your character, nothing mechanical, so no need to homebrew or worry about balance.

This is fair but what happens to all the class features if the character is disarmed or loses the weapon?  Does the sword still imbue the character with all the features even in absentia?  I guess it's moot with Eldritch Knight with the weapon recall ability, but the other classes, not sure how much I want the power set beholden to what's in the palm of my hand.

Quote from MidnightPlat >>

Quote from pangurjan >>

If you pick a spellcasting class it becomes quite easy to simply say every other new spell acquired is granted by the sword rather than a class feature, for instance, but something similar can be done with just about any and all class abilities. An Eldritch Knight's entire spellcasting ability could be reskinned as being granted by a sword (which would help explain that ability only kicking in at lvl 3 as well), a Paladin's Smite or Channel Divinity features could originate from the sword rather than his oath, a Barbarian's Rage could be induced by the weapon instead of being an internal thing, and so on. The sword itself can be improved through rituals or quests or prayer or whatever you or the DM feels is more appropriate. Your character finding or buying a better weapon is functionally no different than your character finding his weapon has unlocked a new power or deliberately unlocking it himself, after all.

Essentially, you don't have to create anything new for this - just reimagine existing mechanics as a function of the blade rather than your class and agree with your DM that whenever you'd have a chance to acquire a better weapon during the campaign this gets reskinned as your sword becoming stronger. You'd only be changing the aesthetics of your character, nothing mechanical, so no need to homebrew or worry about balance.

 

This is fair but what happens to all the class features if the character is disarmed or loses the weapon?  Does the sword still imbue the character with all the features even in absentia?  I guess it's moot with Eldritch Knight with the weapon recall ability, but the other classes, not sure how much I want the power set beholden to what's in the palm of my hand.

 That's entirely up to what the DM and the player agree on. Could be he needs to be wielding it, could be he just needs to be the nominal "guardian" and the weapon could be 5,000 miles away and still impart its powers, could be anything in between. There are plenty of classes that could in theory have similar issues: paladins breaking their oath, clerics and warlocks getting cut off by their deity or patron, druids and rangers losing their connection to nature, sorcerers and wizards losing access to the Weave. None of that is covered by actual rules, I'm just pointing out that characters losing some or all of their powers in some way or other is kind of a trope.

The backstory sounds like a paladin, but the mechanics are not far from Pact of the Blade warlock. Maybe your DM could make you a Good patron.

Quote from pavilionaire >>

The backstory sounds like a paladin, but the mechanics are not far from Pact of the Blade warlock. Maybe your DM could make you a Good patron.

Celestial Pact of the Blade could work.

Quote from MidnightPlat >>

Quote from pangurjan >>

If you pick a spellcasting class it becomes quite easy to simply say every other new spell acquired is granted by the sword rather than a class feature, for instance, but something similar can be done with just about any and all class abilities. An Eldritch Knight's entire spellcasting ability could be reskinned as being granted by a sword (which would help explain that ability only kicking in at lvl 3 as well), a Paladin's Smite or Channel Divinity features could originate from the sword rather than his oath, a Barbarian's Rage could be induced by the weapon instead of being an internal thing, and so on. The sword itself can be improved through rituals or quests or prayer or whatever you or the DM feels is more appropriate. Your character finding or buying a better weapon is functionally no different than your character finding his weapon has unlocked a new power or deliberately unlocking it himself, after all.

Essentially, you don't have to create anything new for this - just reimagine existing mechanics as a function of the blade rather than your class and agree with your DM that whenever you'd have a chance to acquire a better weapon during the campaign this gets reskinned as your sword becoming stronger. You'd only be changing the aesthetics of your character, nothing mechanical, so no need to homebrew or worry about balance.

 

This is fair but what happens to all the class features if the character is disarmed or loses the weapon?  Does the sword still imbue the character with all the features even in absentia?  I guess it's moot with Eldritch Knight with the weapon recall ability, but the other classes, not sure how much I want the power set beholden to what's in the palm of my hand.

 Perhaps the character is imbued through mediation over a long or short rest similar to the attunement mechanic and it lasts 24 hours before attunement is broken. I could see the potential for a pretty fun side-quest when the weapon is taken in the morning and the party needs to hunt down the thieves before the power is available for the bad guys to use.

At any rate, note there are also no rules for warlocks or clerics if their supposedly external power source is cut off. I think this is left to the DM because different groups prefer wildly different consequences.