I am creating a version of the Rune Knight subclass where Giant's Might, rather than being a granted ability at level 3, becomes an additional rune. You are also able to have 1 additional rune chosen. I think that I've gotten that part to work. A couple things that I need help with. 1. The giants rune (that's what we're calling the giants might rune), when chosen gives advantage on strength saving throws. I thought I had done that part correctly, but it doesn't show up on the sheet. And 2, We are adding a feature where you can get 1 additional use of any rune per long rest. I just don't know how to add this feature at all. 

here's a link to the homebrew subclass. Thanks for any help. 

For the additional use of the rune, add an Action with a limited use of 1.

How did you set up the saving throw advantage?

In the Rune Carver class feature section, I went into the class feature options, where the Runes are, added a Giant Rune (for Giant's Might), in the giant's might rune I went to modifiers, I selected advantage in the first box and strength saving throws in the 2nd box. 

That should do it. Maybe add something to the Description field so it has something to put in that window on the sheet?

I did put "advantage on strength saving throws" in hopes something would show on the character sheet, but it doesn't. 

Did you remember to re-save the whole subclass?

I did. Not sure why it isn't showing up. . . 

That Modifier is attached to a class feature Option, correct? That may well be the reason. The more nested something is, the more chances it has to not work properly.  Either that or your character sheet is stuck on an old cache. Try it on a fresh sheet and see what happens.

It did eventually show up. Thanks!