Who is Scud East from Flashman in the Great Game: From the Flashman Papers 1856-1858 and what is their importance?

Scud East went to Rugby School with Flashman. The two last saw each other when Scud abandoned Flashman to the Russians in order to leave and get integral information to headquarters, something for which Flashy seems unable to forgive him. Scud dies in Flashy's arms.