Marwyn, the Nurturer | Illustration by Chris Rahn Elf commanders are legendary creatures (and one planeswalker!) that either have the elf creature type or otherwise interact with elf cards
Conversely, if a Hades you control is dealt lethal damage by a spell you own, the spell will be exiled, and then Hades will be exiled as well
The deck also has some pretty huge creatures for you to discard then bring back onto the battlefield for free with your commander
For Colorless Matters we've got ramp with Shrine of the Forsaken Gods (it's like Temple of the False God but, uh, NOT TERRIBLE), mana-fixing with Corrupted Crossroads, and cute utility with Tomb of the Spirit Dragon and Ruins of Oran-Rief
Hard-Hitting Question: A punch for one mana all but puts Prey Upon out of commission, unless you want to trigger fights. Rope: Reach, a buff, and a way to make your menace creatures unblockable
However, more than many other Commander decks, Szarekh seems to be in service to the 99, instead of the other way around