Tuan Mac Cairill (Forerunner)

See also: Fintan mac Bóchra (Forerunner)
Could Tuan Mac Cairill actually be Cain? It would explain his ability to survive, and apparent inability to die since he continuously reincarnates. 
Could he be a Forerunner to the Druids? Since he can also transform into Animals?
Could he actually be Tuan Mac Cairill? Both survived the plague and were able to turn into animals?
In Irish mythology Tuan mac Cairill was a recluse who retains his memories from his previous incarnations, going back to Antediluvian age. Initially a follower of Partholon, he alone survived the plague, or the Flood, that killed the rest of his people. Through a series of animal transformations he survived into Christian times, and, in conversation with St. Finnian of Moville told a brief history of himself and of Ireland from his people onward to the coming of St. Patrick.