I got this idea from build three of http://www.mobafire.com/league-of-legends/build/unforgivens-guide-how-to-build-a-successful-mordekaiser-24061 build where he uses three hexteck gunblades. I realized the potential of spellvamp and lifesteal on kaiser so i built him my way. I like to play kaiser as a support in the offensive tree because his ability gives you shield based on how much damage you deal with abilities. Dealing more damage = more shield.

Usually the order i get my items in and i like offspeccing in defense tree because momordekaiser doesn't have any other ways to save himself and dodge is really good.