If {Scion of the Ur Dragon} becomes a copy of say {Hellkite Charger} would he still inflict commander damage as he is no longer Scion?
Yes he becomes a copy of with the same power toughness and abilities until end of turn
ummm to clarify yes. the commander characteristic is locked into a card once you announce it as your commander. otherwise playing with {the mimeoplasm} would be a pain as a commander.