If I had infinite resources to have every hero up and running, there is one I would leave at purple, and that's not exaggeration.
Le Angelic Herald.
He was ldesigned as support but in practice literally has no skills, the health of ill chiken and damage of Angel Dragon (spoiler, none).
Even if runes will be deleted and you give me him with the perfect runes from S1, I won't take it.
Also his looks.
I legimately believe Sven made that hero by the image he hated the most.