Gunblades been busted long before Leblanc.
Watching a 0-5 mordekaiser bash an adc while being stupidly tanky or watching an akali get bashed in lane where any other champ that doesn't rush this item would be irrelevant, then be 0-10 or something and easily assassinate multiple people in a few seconds with proper spell rotations. Both of these scenarios happen way too often when these champs are picked, and this item is super overloaded. Decrease the active damage by a ton and lower spellvamp + lifesteal. I don't think this item is bad on any champion.