I am currently on the final phase of ET but I can't get passed the 4
berserkers at the beginning without completely wasting all my healing items
so I can't use them against the bosses. can some one post a strategy that
works against them. (berserkers are these enemies that weild huge swords and
turn red half way through the battle).

Those guys you refer too are called "White Knights" and they're a pain in the cable cord, but I have a remedy for that. Equip the Dark Dragon sword, wall run and come down with a Y attack to exacute a divine cicada slash, be ready to move from their attacks because even if you damage them, your attack does nothing to their movements, then pick another area of the wall and repeat. I hope this helps.

Actually, they are called Berserkers (tho Arctic Inferno clls 'em "White Knights"), and what I do is let them gaurd break you, roll cancel (AKA, roll right when you get gaurd broken), then forward+Y with the DDB. Eiththat, Wind path off thier heads and on Landing (OL) forward+Y. Use the essence for a UT. repeat. Doing this, you shouldnt need to heal.