Wally could be developed by showing his growth in character. For example, if he was a bit cocky before, he could return more humble and with a deeper understanding of the world. This change could be a result of his experiences while he was away.
Well, I really like the fanfic 'Wally West: Racing Against Time'. It's a thrilling read as it pits Wally against a new and powerful enemy that can manipulate time, which creates a whole new set of challenges for him. Then there's 'Wally West and the Lost Speed Force'. This one is more of an emotional journey as Wally tries to find his connection to the speed force again. And don't forget 'Wally West's Allies and Adversaries' which gives great insights into the characters he interacts with.
Wally West's speed in the comics is off the charts. He can move at velocities that surpass the limits of normal comprehension. His powers allow him to zip around and perform feats that seem impossible to others.
In certain comic book runs, a black Wally West has made appearances. This character variant has added diversity and new story possibilities to the comics.