To beat the final boss, Chaos, in Final Fantasy 1 Pixel Remaster, follow these detailed steps:

1. **Prepare Your Party**
– **Leveling:** Ensure your party is well-rounded and at a suitable level. Levels 25-30 are generally recommended, but it can vary depending on your party composition and equipment.
– **Equipment:** Equip your party with the following items:
– **Masamune:** A powerful sword that can be equipped by anyone.
– **Excalibur:** A powerful sword that can only be equipped by a Knight.
– **Katana:** A sword that can only be equipped by a Ninja.
– **Defender:** A shield that casts the Blink spell in battle. It is good for a Red Wizard.
– **ProRing:** The best hand gear anyone can wear.
– **Heal Staff and Heal Helmet:** These items cast Heal when used in battle.

2. **Master Your Spells**
– **Haste and Temper:** Cast Haste on your strongest attackers to increase their speed, and Temper to boost their physical attack power.
– **Protect:** Have your White Mage cast Protect to reduce the damage of Chaos’s physical attacks.
– **NullAll and Wall:** Use NullAll to reduce all incoming spell damage, and Wall to further protect your party from spells.
– **Healga and Cure:** Keep your party’s HP topped up with Healga and be prepared to use Cure spells to counter Chaos’s healing abilities.

3. **Battle Strategy**
1. **Initial Setup:**
– Equip your best fighter with the Masamune and have them use the Giant’s Gloves to increase their physical damage output.
– Cast Haste on your strongest attackers to maximize their speed.

2. **Defense Phase:**
– Use NullAll and Wall to reduce incoming spell damage.
– Have your White Mage cast Protect to minimize physical damage.
– Keep your party’s HP high by using Healga and other healing items.

3. **Offense Phase:**
– Wait for Chaos to use Cure4, which restores all his HP. This is a critical moment to attack him before he can heal again.
– Unleash Flare, Holy, and other powerful spells on Chaos. If you have a Black Wizard, use Flare as it is one of the strongest spells in the game.

4. **Healing and Support:**
– Ensure that your White Wizard is equipped with Heal and Cure spells to keep the party alive.
– Use Heal Staff and Heal Helmet to supplement healing needs.

5. **Predicting Chaos’s Attacks:**
– Chaos has a list of spells and special attacks that he repeats. You can somewhat predict what he will do next, which helps in planning your strategy.

4. **Additional Tips**
– **Luck-Based:** The battle can be luck-based, so be prepared for unexpected turns. If Chaos uses Haste on himself, it can make the battle much harder.
– **Party Composition:** The effectiveness of your strategy depends heavily on your party composition. A well-rounded party with a good balance of physical and magical attackers is crucial.

By following these steps and strategies, you should be able to defeat Chaos in Final Fantasy 1 Pixel Remaster.