So, I was messing with the new files that was released here a few days ago and I managed to add the Eidolon Ares on the game.
The Eidolon can be summoned, he can do basic attacks... But none of his skills are usable/working. The icons are already in the client, so are the translated descriptions.
When I put these
S_Spells.ini edits the server crash with LP_READ_ERROR.
EDIT: SOLVED!