Golem Core

A Golem Core is a piece of forgeable material in Golden Sun: The Lost Age. It is described as "An Earth Elemental's heart". It is found in various areas after the Great Western Sea is accessed, such as in Loho, and it can also be dropped rarely from a Bombander in Anemos Sanctum (fell it with Mercury Djinn to increase drop rate by four times). Being an Artifact, it can be sold and later repurchased. It can be bought for 1500 coins and sold for 1125 coins. It can be forged into the following quite powerful equipment:

Chronos Mail: Armor class: Defense +47: Maximum HP +20. It is bought for 13100 coins and sold for 9825 coins. The chance of it being forged is 30%. Gaia's Axe: Axe class: Attack +163: Unleashes Mother Earth, which converts to Venus damage, adds 56 attack points, and has a chance to put the target to sleep. It is bought for 16400 coins and sold for 12300 coins. The chance of it being forged is 15%. Huge Sword: Long Sword class: Attack +155: Unleashes Heavy Divide, which converts to Venus damage, adds 60 attack points, and cuts enemy defense by 25%. It is bought for 14000 coins and sold for 10500 coins. The chance of it being forged is 15%. Titan Gloves: Glove class: Defense +43: Maximum HP +30. It is bought for 8100 coins and sold for 6075 coins. The chance of it being forged is 25%. Tungsten Mace: Mace class: Attack +159: Unleashes Hammersphere, which converts to Venus damage, adds 51 attack points, and may lower the target’s defense down to 50%. It is bought for 14700 coins and sold for 11025 coins. The chance of it being forged is 15%.

Analysis
Golem Core weapons are strong, though ideally you would have even better weapons than those by the endgame. The Chronos Mail and Titan Gloves are often worn for their strong defense ratings and good HP increases, though again, there are better endgame alternatives.

Random Number Generator methods
Here is the RNG method for how to get the Golem Core.

Golem Core can be dropped by Bombanders in Anemos Inner Sanctum. Standard rules apply.

Party order: Felix, Jenna, Sheba and Piers. Order of attack: Sheba, Jenna, Felix and Piers. Save the game anywhere in Anemos Inner Sanctum, turn off the Game Boy though and reconnect it. You must first find a Bombander and another monster, if not, turn off and turn on the Game Boy again and keep trying until you find it.

Round 1
 * Sheba casts Shine Plasma! Large arrow: Bombander
 * Jenna casts Aura!
 * Felix casts Mother Gaia! Large arrow: Bombander
 * Piers casts Glacier! Large arrow: Other Enemy

Round 2 You felled Bombander!
 * Jenna and Sheba defends.
 * Felix attacks! Large arrow: Other enemy
 * You felled other enemy!
 * Piers unleashes Gel! Large arrow: Bombander

You should receive the Golem Core.