Before you begin the battle:

The MA-X Angelus will only spawn after you have completed the entire main story of the game. It is a level 99 optional enemy battle that is really tough, especially if you aren't level 99. The trick mainly is to hit its body or when it releases rockets. This can be difficult at times but I have come up with some tips after fighting several of them for hours. Also, note they drop two versions of the Magi-tek suit which is a very powerful accessory item. They will drop Magi-tek suit version 1.0 and 2.0. The latter version is rare, with a 3-5% drop chance and more powerful.

It will increase maximum hit points, as well as vitality and strength.

The first thing you should do is look for the Angelus. It can spawn in various areas throughout the game. I found the most spawn points near the Midgardsormr snake which is at the plunge waterfall area or the Grotto dungeon area.

Angelus in the fray:

After it spawns, quickly hit the pause button and go to options. It may be cheap but it will save you valuable time. Switch over to easy mode and then simply die. You will see the words Ruby Light appear on the screen. This is the easy mode carbuncle buff which will increase tons of statistics for your party.

Afterward, you may be best suited with the Zwill cross blades. If you don't have those use Ulric's Kukris, and finally, if you have neither, use the strongest pair of daggers that you have.

Keep teleporting to its square body and attacking. Let your armiger build up and use the Enhancement technique with Ignis as often as you can. Once the armiger is full you can release it and use tons of attacks. Do this until it is almost depleted than release your Armiger chain attack. It should not take too long for the MA-X Angelus to go down this way and you will save tons of procurement items.

Finally, If you want an even easier time, go to a campsite first and eat the highest critical hit increasing meal you can find. If you don't have the best one, try fish sticks on sticks. As a matter of fact, any critical hit chance increase is worth your time to save you time for this exceptionally tough fight. You will gain a good amount of experience points, and the Magi-tek suit. Keep farming with this method to get as many Magi-tek 2.0 suits as you would like.