I considered playing a second Pyrite Spellbomb instead, as a lot of the time you want Pyroclasm, youre only really trying to kill one creature, and its relatively painless to draw when its bad instead of completely blank
First, at the time, we didn't let black kill black creatures
Wyleth, Soul of Steel generates a ton of free draw off of your equipment, and Galea, Kindler of Hope can help you skip those prohibitive costs
Mondrak, Glory Dominus has a similar effect and has seen regular play since its release in Phyrexia: All Will Be One, thanks in no small part to the ease with which it can be granted Indestructible
This is due in no small part to Spellstutter Sprite, one of the best counterspells-on-a-body in all of Magic
It will be especially good in decks that can use -1/-1 effects