Puck originally became a dwarf when the sorceror Raazer possessed his body, shrinking his size but increasing his lifespan. Raazer was removed from his body, but he returned to his true 80-ish age. Later, after genetic manipulations by the Master, his full-sized mass was compressed down into a highly durable new dwarf state. Seagle did not address this throughout the 2nd series.
As of Alpha Flight (3rd series) #12, there were two versions of Puck running around -- a past version on Earth, and a present version on Plodex. One was killed on Earth in New Avengers (1st series) #16 but it wasn't clear which one. Five years later, Chaos War: Alpha Flight #1 established the original Alpha Flight returned from space before being killed by the Collective. The past versions were presumably restored to their proper place in history.