The Odin Sphere remake had Cornelius doing spin slashes and shooting sword beams, so I knew what I had to do.

To install, use an IPS patcher of your choice and apply it to a headered US copy of A Link to the Past.

This patch modifies:
All of Link's sprites (including dark world and his wanted portait)
Tunics were turned into rings from Zelda 1 because Cornelius doesn't wear a tunic
Some of the NPC sprites
Some of the game text to go with the above changes