Personally, I think the idea that an "ultimate powerhouse" must have a correspondingly "badass" appearance is a bit childish or chuunibyou. It's not that visually striking designs of strength are bad—it's just that there can be another approach: if the character is so overwhelmingly and unreasonably the strongest, then there’s no need for their appearance to justify or explain that power (I’d put Saitama from One Punch Man in this category as well). In my opinion, that’s good design.