Story: the "evolution" of the man made Pokemon J0-X (referred to as Jox) the first synthetic Pokemon Prof maple managed to create although its body was even more unstable then Ditto its memory and creativity let it take many forms of Pokemon and mix and matched parts to create an "optimal" form for each battle how ever there was a critical error. after it and its partner Willow are beaten over and over by Jasper and Zelgadis (Willow and Jox are not the kindest people to other Pokemon and humans) they discovered Jox's unstable form made it to easy to defeat by just separating its mass it had to be fixed affixing mechanical parts to Jox it became more solid still able to transform creating Mk. 2 how ever the added energy causes Jox's cognitive functions to suffer so a containment body was made a metal canine like form (a form created from scanning Jox's mind off his version of a perfect body likely a tad jealous of Willows obsession towards making Zel her own Pokemon) in this contained from it is much like a normal Pokemon around sub legendary power how ever when released its power is like that of the mega mewtwos or even beyond but this form cant last if Jox stays out of his containment body to long not even willow would be able to stop it
details: the metal body is incredibly durable and mobile it covers Jox's whole body with the acceptation of its feet and tail which are formed by Jox's inky black malleable body its face has a clear Window for Jox to see through (all though not visible Jox does have a "face") attached to its chest is the mask the pokemon used to give itself a face before its upgrade
J0-X is typeless
this is possibly not the finalized appearance or story
for a look at this pokemon original form and its trainer: https://pokecharms.com/works/jasper-and-willow.49758/