Write him in the Thrawn Trilogy.
Galen fighting some sort of personal mini-conflict against Joruus C'baoth would be sort of neat. Have C'baoth set Galen up in a duel with an evil clone of himself. When the fight is over, Galen leaves, but the viewer doesn't know if the clone survived or the real one.
"There is something going on in time and space, and beyond time and space, which, whether we like it or not, spells duty." -Winston Churchill
"For of all sad words of tongue or pen, The saddest are these: 'It might have been!'" -John Whittier
"Apathy is death." -Kreia