I'll use it...eventually. :)
At times, I like looking at Blue Gyarados rather than the Red one. However, I am not passing up a Shiny encounter! I plan to train all Shiny Pokemon I encounter anyway, so...
As for the nickname, either Skul, SkulKrakr, or a variant thereof. My reasoning is because the original name of Gyarados was going to be Skullkraken, IIRC, so I'm going to highlight my Gyarados' ability of "cracking" skulls apart. Crushing would probably be a better verb, though, but SkulCrushr as a nickname seems weird at the moment...