As long as Gravis was so big, he didn't truly feel like a human. Another problem was that his Battle-Strength was severely affected by this new form.
This new form of his had basically crammed everything of his old body into this one, making it feel bloated. His normal form had much more space with a longer and broader neck and wider chest. His arms were also much bulkier than normal. Additionally, one shouldn't forget that his legs had a very different shape.
Gravis' whole body felt bloated like his insides and muscles wanted to spill out. He was pretty sure that the skin on his arms would explode if he tried to punch something. Moving his legs also felt awkward with the stretched and constrained muscles.
Lastly, one shouldn't forget that a human's body was not as combat-focused as Gravis' beast body. Right now, properly fighting in his human body felt very uncomfortable.
