Loxi: Rodolf is cool, but he's a bit expensive and combines two archetypes that might be a bit hard to slap together
The original Teferi, Mage of Zhalfir design is nearly 20 years old by now and still quite powerful
Using Belakor, the Dark Master turns the deck into demon tribal, turning demons in play into card draw, as well as making demons entering play deal direct damage
Try to give yourself access to a diversity of removal types, including targeted spells like Blink of an Eye, board wipes like Akromas Vengeance, and exile spells like Angelic Edict in case your opponents cast something indestructible
Entropic Uprising Every set of Commander decks since it debuted in 2011 and continuing through today has created new archetypes, giving Commander players more tools, and such