Source: villains.wikia.com

3. Dr. Hurt

Dr. Hurt was created by Grant Morrison, and as such, you can assume that he was really REALLY weird.

He’s either Bruce Wayne's father OR an ancient devil worshipper OR a demon that has haunted Gotham for centuries OR a trans-dimensional minion of Darkseid OR some combination of all or some of those things. That’s our starting point. So look, I read Batman RIP, and I'm a pretty well-versed Batman scholar (still training to be an official Batman-ologist), but even I needed help putting all of this together.

Here's what I got: Thomas Wayne was an ancestor of Bruce Wayne. He's not THE Thomas Wayne, but Bruce's dad might have been named after him. He was also a devil worshipper, and tried to summon Barbatos, a demon who may or may not be the same as Barbathos, a bat demon summoned initially by Thomas Jefferson, who later possessed The Riddler during Dark Knight, Dark City. Instead of summoning the demon, however, Wayne accidentally made contact with the Hyper-Adapter, a minion of Darkseid sent back in time to track and monitor Batman during his own journey through time after being hit by the Omega Sanction after shooting Darkseid. The Hyper-Adapter either fused with or corrupted Wayne, and changed him into Dr. Hurt, a crazed man who wanted to ruin the Wayne reputation, and did so by establishing the cult of the Black Glove. Eventually, The Joker killed him, putting an end to this very strange and confusing saga.

Also, there's WAY more to him but I'm already way over my allotted word count.