For each life you pay in addition to paying the cost, each creature gets -X/-X
You choose the order in which those triggers go on the stack
cEDH viable for sure, and is very strong outside of that too
Among all of the scant 4 examples of this piece in PSA's census reporting, this is the sole piece at this unimprovable tier
For a finisher with villain flair, Bolass Citadel lets you cast off the top of your library by paying life instead of mana, then sacrifice 10 nonland permanents to drain each opponent for 10, a fittingly dramatic monologue before the win
Legendary Creature - Avatar Sideboard (CTRL to add secondary) Maybeboard Consult the Star Charts Kicker (You may pay an additional as you cast this spell.) Look at the top X cards of your library, where X is the number of lands you control