With all this damage you'll be dealing, Neheb, the Eternal is bound to generate lots of mana (with which to fuel even further firepower)
If it were instant I think it would be comparable to the other best removal cards in all of magic
Hallowed Burial and Final Judgment both have their uses, though again, can be a little limited in scope
It's got lifesteal that already makes it a formidable creature, but can be paired with Marauding Blight-Priest for an instant win button
Then you have an array of borderless, foil treated, and alternative art versions of the cards discussed above, which all fetch a premium to their base printing
Cards like Reckless Endeavor that let you roll multiple dice are your best chance of giving this commander trample