in game hero abilities change

I know that it is posible to change the abilities of a certain unit in game, but is it also possible to change the HeroAbilityList in game using triggers?

Of cause in TFT.

i read a thread like this sometime ago and the conclusion was that u were able to change the ability's of a Unit, but NOT a Hero..
but if you want the hero change some ability's u can just make another unit and replace the old unit with the other one--- thats also a way of doing it :D

the problem i face is the following:
i want to make an rpg map where the hero is able to choose from a huge list of abilities which he wants to be able to learm so that every player will be able to make his own combination of skills.

And also another question: is it possible to make a hero use more then 5 Heo skills? And if yes then how?

I know that if you change the maximum of hero skills in the UnitMetaData.slk it only affects the editor, but not the game. Any ideas?

You could add a skill to a unit easily enough, but hero skills are much more problematic. Here's a question for you, though - do you NEED the skills to be hero skills, or can they be unit skills?

If they can be unit skills, find out how to do Spellbooks. You'll probably have to make a whole bunch of them, but in addition to the 4 main hero skills, there's room for 2 spellbook skills, each able to house up to 11 more skills (I'd argue that 22 more skills is probably overkill). It might be a little tricky to have them buy skills, since you can't really just add a skill to another skill, but it's a start.