Emerald Weapon (Final Fantasy VII)

Emerald WEAPON is an optional boss in Final Fantasy VII and one of the toughest of the four WEAPONs to defeat (the others are Ultimate, Diamond, Ruby and the non-battled Sapphire). It is one of the creatures that Sephiroth sends out of the Northern Crater to cleanse the planet of humanity.

Emerald WEAPON is located under the ocean, accessible by the Submarine. A battle will ensue after making physical contact. You'll have 20 minutes to complete the battle unless you have the Underwater Materia equipped.

One of the things that makes Emerald one of the strongest of the WEAPONs is its Aire Tam Storm; this caused fans no end of trouble when they first played through Final Fantasy VII, but the clue is in the name of the attack. "Aire Tam" is actually Materia spelled backwards, which suggests that the attack has something to do with the party's equipped materia. It turns out that the attack deals damage to each character equal to the amount of materia equipped on them multiplied by 1111. As such, having nine materia crystals or more equipped on a character meant certain death. Honing of strategies has resulted in the widespread defeat of Emerald, as players have learned to make the most out of as small an amount of materia as possible.

Strategy 1
This battle can be won in 1½ or 2 minutes, but the actual preparation takes hours and hours of work.

First of all, max out Barret's stats. He must have learned his Level 3 Limit, Ungarmax, and have it ready to be used at the beginning of battle. He must also have 8 mastered Mimic Materia, each paired with a mastered Counter Materia, equipped. The battle should be fought using only Barret and a secondary character, who has a higher speed stat. Start off the battle with the secondary character using W-Item to throw two Hero Drinks on Barret. After that, simply have Barret use Ungarmax. Emerald WEAPON will counter-attack with Emerald Beam, which activates a chain of Ungarmax by Barret, so just let the materia do its work. Emerald WEAPON should be dead before the chain ends. Average time is about 2 minutes from start to finish.

Strategy 2
Start by casting W-Summon using Bahamut ZERO (paired with Quadra Magic) and Knights of the Round with your second character. Have Cloud mimic the summonings. This combo will allow Bahamut ZERO to be cast 4 times and Knights of Round once afterward. Keep mimicking with Cloud, skipping other characters' turns. After several Bahamut ZERO and Knights of Round attacks, Emerald WEAPON will probably try to kill you with Aire Tam Storm. Phoenix will revive your group and you'll have to start the combination over again.

Strategy 3
Have a mastered Phoenix materia paired with a mastered Final Attack Materia. This will allow your characters to come back to life 5 times in total. If you are using relatively maxed out characters with their level four limit breaks unlocked and the Knights of the Round materia with W-Summon. With this strategy, there should be no need to use the Underwater Materia in this battle.

Strategy 4
This is the fastest way to beat Emerald Weapon, however it is an exploitation of the Death Penalty Glitch. Once it is realized, go equip the "Sneak Attack-Deathblow" Materia combination (both mastered of course) and Vincent will kill Emerald in one shot.

Whatever your strategy, after you've defeated the Emerald WEAPON, you'll acquire the Earth Harp. You can exchange this with the man at Kalm for three Master Materia.