Originally Posted by HonorableGeneral
Rumble basically demonstrates what happens when you push someone too far. He's the foil to Heimerdinger - Rumble being the cynicist to Heimerdinger's idealism.
I'm not excusing Rumble's behavior - he's far from a nice guy, and I wouldn't condone his viewpoint considering that Yordles and Humans need not be enemies - but it's not like he's a 'Yordle Supremacist'. If anything, that title belongs to Veigar - except he's more a "I'm better than all of you" versus "My race is better than all of you".
Veigar is an odd case.
If I recall his JoJ scheme to steal the Bandle City Mothership with enchanted baloons correctly, he seems like he wants to be the villian, but at the same time wants some kind of acknowledgement from other Yordles.
He didn't actually hurt anyone, he just put together an extremely short-sighted scheme that almost looked like an attempt to be the center of attention.
My theory is that Veigar is emotionally scarred, but puts on the Villian act to hide it and appear strong emotionally while still having the inherent Yordle need for positive social relationships, which he was denied in his Noxian imprisonment.
(Rumble, on the other hand, seems comfortable being a loner. This is odd for Yordles, as they are stated to require more social interaction than humans.)