1 april idea

People hate the Draven day, so your idea wouldn't make a difference.

The big problem here is dev time. Part of why the Draven idea didn't really pan out well (I suspect) is that the same size head was copy-pasted onto every champion, with often gimmicky effects. Had there been the resources available to actually mesh Draven's head with every model in a meaningful fashion I suspect the day would have gone over better.

Rebuilding ALL graphical assets with LEGO effects would be an astronomical undertaking -- far beyond even Riot's capability unless they devoted most of the art team to the task for the better part of a year. Not really worth it, especially for a few days of goofing off.