[quote=@Masaki Haruna]
Chrome's rival as in..... Like how Gray is to Lyon.
Everybody be stripping....

Posted. One can simply fanboy and fangirl to Cobra. 
NOTE: Just because Cobra is canon here doesn't mean he is part of the 7 DS. We'll get our own original DSs made by future players or you and me.
[/quote]

Wait, wait, wait, Chrome as Yuu utilize two very different magics. Even Yuu's puppets can't utilize ice.

Unless it's the general level of rivalry of power levels, and not at Gray's and Lyon's obsessive need to beat each other(more the latter than the former) near the start of that arc.