>>27163354>>27165461I really like this design and I think it works well as a stand-alone Pokemon, but it doesn't work as an eeveelution. As much as I think the arced back, thin neck, and large eyes look good with the other shapes you're using, if you want it to look more like an eeveelution, the back should be straighter, neck thicker, and the eyes smaller. Larger eyes made sense for Sylveon since it was a Fairy type, but they don't really make sense for a Fighting type (imagine if it was cage fighting and got easily socked in the eye by a Hitmonchan). A thin neck doesn't really make sense for a Fighting type either because it implies frailty. Study other Fighting types; the only one I can think of with a super thin neck is Medicham, but that's because it has gigantic legs already for the sake of making them stand out. Look at Mienshao; it achieved the slender body look while still maintaining stockiness that gave it strength.
I do like the bipedal idea but again its anatomy needs to be altered if you want it to look more like an eeveelution. If you study the eeveelutions' back legs, their feet are really quite small compared to what you have (study artwork of them sitting and on their backs). I understand you wanted to make it kangaroo-like but when you take too much kangaroo anatomy it just ends up looking like a completely different animal (way too marsupial like to fit in with the other eeveelutions, which are more canine/feline-like). The bipedal one you have currently almost looks like a mouse because of the super long lower legs/feet, shortened/nonexistent shin joint, lack of/streamlining of shoulders, minimalization of front legs compared to back legs, size of the head compared to the body, forward ear placement, and vertical minimalization of snout. Again I'm not trying to say these are bad things, as they could be considered smart design choices otherwise and look quite appealing, but for an eeveelution they just don't make sense.
