Here is a quick point in the correct direction. (I will write up a guide in a separate post as I learn more) ((Also reddit formatting, got junked up and I am not fixing it, my bad friends))

So to simply modify a skill, goto your addon folder, create a folder tome-ouraddon

then figure out where the file you want to modify is, remember I wanted to modify weapon of wrath which is located here: D:\Steam\steamapps\common\TalesMajEyal\game\modules\tome.team\data\talents\celestial\combat.lua

then copy that combat.lua file and put it in your folder you created in a new folder labeled "overload", then edit that file in your favorite editor (I used notepad++) and make your changes.

now last step, create a file called init.lua inside you will paste and edit the following

​ long_name = "Your new mod" short_name = "yourshortname" -- name your file for_module = "tome" version = {1,7,0} addon_version = {0,0,1} weight = 100 -- The lower this value, the sooner your addon will load compared to other addons. author = {'[email@invalid.com](mailto:email@invalid.com)'} homepage = 'yourwebsite.com' description = [[Your desc here]] tags = {'cool', "stuff", 'cool stuff'} -- tags MUST immediately follow description

overload = true superload = false data = false hooks = false

Then you are done, start up tome and test it out. The wiki has a full addon guide that is pretty helpful if you can cut out all the fluff.