Not only do both of those cards happen to be at exactly the right spot on the curve to find us our combo pieces, they also can fetch us a Wastes if we need to start the combo by tapping lands
For $0.50, it won't hurt your budget to even try it in your deck(s) and it's also 6 mana
Deathtouch is invaluable with pingers that deal damage to creatures
If either target is an illegal target as Super Combo resolves, the creature you control won't deal damage due to the effect of that copy of Super Combo
Nethroi, Apex of Death 7 hard-to-cast mana which, like all mutate cards, is asking to get blown out, and Nethroi, Apex of Death doesnt get you a whole lot for the risk
While it does have some potent effects, its a tricky thing to manage in a lot of constructed formats as theres so much good removal available at the moment