This is a commonly known archetype in the development world. Since it's commonly known I figure it's a great place to start this series of posts.
Sporadically swooping into meetings with the rest of the team from his namesake home, the Ivory Tower Architect loves to show his mastery of software design. Whether it works in practice or not matters not to him. The rest of the development team is left to implement the grandiose plans handed down from on high, but the Ivory Tower Architect will never work directly on the code himself. Often the designs are overly complex and time consuming to implement, but he will not change them. To do so undermines his very existence.
Dealing with the Ivory Tower Architect requires a strong will, the willingness to have long winded and abstract design debates, and an almost fanatical adherence to the KISS (Keep It Simple Stupid) principle. Lucky for you the Ivory Tower Architect will only rarely grace mortal developers with his presence.