Enter a battle and take a substantial amount of damage. Then, find a spot
to teleport and regenerate your HP and MP - it has to be one where
Noctis basically hangs there with his sword. Execute a companion technique
while you are regenerating your HP and MP (Prompto's Stinger works well).
When the short QTE for the follow-up strike occurs, execute it.
You have to not have fully regenerated your HP and MP by this point
for the exploit to work. HP and MP regeneration will now keep happening
until you end the game or load a save.
Note: This glitch was performed on an unpatched version of the game. It will
probably eventually get patched. To avoid not being able to use this exploit,
either do not install new patches before using this exploit or delete the
patches. You can avoid patches being installed by disconnecting from the
internet until you are ready for the game to install new patches.
The Apocalypse is the best weapon with attack of 597 and boosts HP up to 403.
In order to get the Apocalypse greatsword, you need to complete the
full story campaign. After that you need to get the Dungeon Seal Key
by completing the specific dungeons. Once you have got the key,
you need to take on the quest called A Menace Sleeps in Balouve.
After taking the quest, go to the Balouve Mines dungeon.
In the dungeon, you will come across the boss whom you need to defeat.
The enemies here are level 75 so if you are lower in level make sure
to use some legendary weapons. Near to that place you will find a small gap
in the wall, in which you will find the secret dungeon door.
Enter inside and keep going until you come across Apocalypse.
You will find it on the floor at the first camp site which is
found 5 floors down to the place you are right now.