Good afternoon,

As the title indicates, I am trying to attempt one of these options in an effort to simulate the Spells of the Mark Dragonmark feature from the newly updated Dragonmark Subraces. All I have been able to accomplish so far is a Staff of Power effect whereby the item can cast all of the spells for charges that reset daily, but the main thing I'm looking for is adding them to the spell list and or as once per day spells.

Any thoughts or help would be appreciated.

Thanks,

There is currently no way for anything except certain Ravnica backgrounds to add spells to a Class spell list. This is why the developers, who have access to more tools and the raw code, still haven't been able to implement this yet.

In meantime, I just recommend making a copy of the subclass and editing it to add the spells. 

Have you tried implementing the use of feats? If you make a copy of Triton to see how they do those daily spells, maybe you can utilize that to create a feat that does what you want it to do. That's just what I've previously done. Maybe you can give that to the player and just put the wording for it to work how you want it to work.

Yeah, items can't do what you are wanting. The most complete way is to make a subclass. Feats are next closest, but not perfect.

Once per day/long rest spells can be added via homebrew to items, feats, or subclasses. In order to have a spell show as always prepared in the spell list, a homebrew subclass is the only way to do it. 

My workaround was to make a homebrew copy of the spell but include the class your character is.  

So for example, I made a copy of Silence, changed the name to "Silence (Mark of Scribing)" and added Artificer to the list of classes it applied to.

Seems to work a little easier than the other ways of going about it.