Unlimited stealth shield:
 Once you can get the stealth shield from Walks home 
 world, you can keep getting more by telling him the 
 fact again. This is useful in trades. 
 The stealth shield brings a high price, and can get 
 many Quietus Missiles from the Phelonese, which kill 
 anyone in one shot. However, you can only carry 255 
 of any item.