This page is inline with Celtic Weaponry is all about the Celtic Sword. Below is some information about the sword.

Always the favored weapon of the Celts, the sword underwent change over the centuries as it progressed from the simple bronze-bladed leaf shaped sword to the relatively modern swords you can still see in Scotland and Ireland today. Although mostly seen in museum displays, more modern versions of some of these blades are still carried on ceremonial occasions.

The Celts did not weild their swords in any fancy or particular style, mainly they were used in a strange motion not in the normal slash and stab motion favoured by the vikings, saxons or romans. They were either used in a straight forward stab or in a strange backhand slash.
The larger weapons like the claymore and broadsword where used in a downwards swing, this was used as it expendid less energy, because you would not be suspending it in the air as you would for a horizontal strike, and you didn't have to put much of you own strength into the downwards blow as gravity would drag a claymore down to the ground with enough force to crush a mans skull.
As i said befor they had no style just the simple will to bring about enough deadly force or movement to dispatch an enemy.