This colored sketch was made by the wonderful  Heartman98

Along with most pokemon after reaching a certain skill cap they would evolve if given the right prerequisites, Echo is however no exception to this. However during evolution he ended up skipping his frogadier form, causing his skin to be much lighter than a normal greninjas. And due to the irregular jump from froakie to greninja their ability also changed to one unique to them. Based on what berry or pokemon they devour and stuff in their gut, the icon on their belly would change to that given type and give off a buff based off said type, for example if they devoured a pikachu their gut icon would be that of the elec icon and give them immunity to paralysis and makes elec moves only normal in effectiveness. The icon on the gut by default is the water type icon which gives off an aquaring effect along with making their water moves pack more of a punch. Each type's symbol would be based off of the icon used for energies in the pokemon trading card game. However if the being they devour doesn't have an affiliated element it will either go to the default water icon or become one fit for the given being in Echo's gut along with granting a unique buff to them. For example say if he devoured a starbound character, he'd have a star on his gut and be granted the ability to jump high(this is just an example not an actual given buff). Course this ability took the place of what would have been protein meaning he doesn't have access to a greninjas main ability such as torrent or the hidden ability protein.

Figured it was time to evolve Echo but I didn't know how to go about doing it, so I brainstormed multiple ideas and thought of one I'd genuinely like. I hope my ideas were good and did greninja as a pokemon justice as heartman did an amazing job sketching and coloring this piece!