If you're looking for positive benefits of your own, you can get lifegain from Ikra Shidiqi, the Usurper, ramp from Arbor Adherent, and card draw from Abzan Beastmaster
The first thing you should do before starting to build it is make sure that the tribe actually has the support to make it workor, if it doesn't, know how you plan to maximize that support
You could also run a deck that doesnt play a lot of mana rocks and want to make sure that you dont miss out on mana
With such a potent answer like Unholy Heat, most of the creatures and Planeswalkers are easily answered, so decks have to play a lower curve threat package to not trade big mana threats against a single Unholy Heat
An iconic card like Ghoulcaller Gisa deserves its spot in the new Commander Collection: Black
You create the Saproling tokens, even if Fists of Ironwood enters the battlefield attached to another player's creature