Claimh Solais

Claiomh Solais is one of the most powerful weaopns in the game and the most powerful weapon in normal mode sans the extra weapons from the time trials. The sword is a holy weapons so it is strong against dark enemies and it has one of the longest reaches of an weapon. It is also swung horizontaly giving it a wide range. To obtain it, Soma must go into the get paste the waterfall into the Forbidden Area and break a wall underwater in the sunken ship room leading to the Claimh Solais

In Mythology
In Irish mythology, Claíomh Solais (IPA: [kɫiːv ˈsɔɫɪʃ]; also known as The Sword of Light) was a sword that came from Findias and belonged to Nuada Airgeadlámh (Nuada of the Silver Hand), who was leader of the Tuatha Dé Danann and King of Ireland. In legend, the sword glowed with a bright light, hence it's name. It was unresistible in battle and had the power to cut his enemies in half.[citation needed] It is one of the Four Treasures of Ireland (the others being the Spear of Lugh, The Dagda’s Cauldron and the Stone of Fal).