Will this basically negate the whole of akuma's e: or just stop one foundation from being commited

Just replace one foundation being comitted.

This seems at odds with the previous ruling (see the post a few below this one) where it was ruled that it would replace the effect before a target was chosen

aslum said:

It replaces one of many. If an effect has multiple targets, it doesn't replace all of them. The other option is to have it not work at all, since JoR states When your opponent would commit 1 of your foundations. However to keep it in line with other cards that have similar text, it saves one card.

How about Torn Hero (which has different text to Journey of Repentance)?

I thought it might stop Akuma's enhance as it reads "When your opponent plays an ability that commits a card in your staging area, they commit this card instead".

I had always read that as "Instead of the commit part of the effect", meaning that it stops the other foundations being committed by Akuma, am I correct?

I understand why Journey of Repentance does not work this way as it states that it commits itself instead of 1 of your foundations, but the wording on Torn Hero seems to indicate that it commits itself instead of the effect.

I asked this, and infact what happens is you react after he plays the ability, commiting and getting to commit 2 of his things. And then you are allowed to choose 1 of the things commited by his ability to be protected by torn hero (i.e. what torn hero is commited for instead). So you could stop a key foundation being commited etc.