I think the line is really clever. Admittedly, it requires some thought though. I think that PSukamon and ILeomon are visually very similar, they're both white and have leather wraps around their arms. Their names, Platinum and Ice are both synonyms of one another in jewelry slang. There's a very popular story called the Lion and the Mouse where a Lion is awoken by a Mouse but decides to spare it's life. That story is referenced in this line, the mouse becomes the lion after going through poo. If you factor into account that the character's name is Nil, meaning zero it's as if the mouse goes from zero to hero.

If you don't like it, I guess I could go for something a little more generic... 

I'd also like to point out that my CS isn't finished yet. I just posted it to see if the code was all working fine but then the site crashed for me and I couldn't get back.