His "Darkness" ability causing you to lose life when he deals damage basically represents his guilt over attacking innocent people on Baron's orders
While spells like Dark Ritual generate mana, they still go on the stack and are subject to interaction
Its my favorite deck that I own by a fair margin, and Ive been working to foil out as much of the deck as possible
If you build it, build it to the nines, with the intent of being archenemy, because you almost always will be
It's quite strong, even if it sometimes causes logistical nightmares on the Commander table
Right now, everyone is leaning on Commune with the Gods and Satyr Wayfinder, both fine cards that give you a little bit of value while you dig for specific creatures or lands