Why is Morphling not played as a support more often? Adaptive Strike when morphed strength is one of the best stuns in the game, he's tanky for a support when morphed strength, and Replicate lets you clone your hard carry in fights (-50% damage). Waveform and Replicate also make him a good counter ganker - an important duty to fulfill as a support in the current meta. I think you build him like Naga support i.e. Arcanes, Medallion, Urn, Halberd...
I should probably give it a go after I finish my dissertation in a few weeks.