I have seen a lot of requests for this one so I figured I'd post my strat.
Get crystals, balis, barricade, floor spikes, wall blades, and bombs. I also take gorks and tar, but both are optional.
Start by dropping a crystal in the sealed room and barricading the rear top corridor.Baricade it in the front so you can put crystals behind it. Now start filling the bottom up with balis. Start in the 2 little notches. Drop crystals in the sealed room and behind the barricade when you can. When you have 4 balis, you can drop a wall blade in the hall leading down. Put floor spikes after it so thieves can't destroy it. Keep filling up the bottom with balis
When the 1st Epic Knight comes barricade him off before he turns into you bali room. Drop bombs on him while he beats down the barricade. Once he gets thru he'll take out some balis, but just replace them. Always drop bombs on epic knights when you can. It will stun them for a sec giving you balis free pop shots or time to reload. You can use tar here to slow anyone coming into the bali room, just be careful not to set your balis on fire with a tar/bomb. When your not replacing balis fill the top with wall blades followed by a floor spike. If you have gorks you can drop a few in the back room just in case, but no1 really makes it back there. Good Luck