MTGNexus

Power Pylon 2
Artifact (C)
Artifact creatures you control get +1/+0.
A deck can have any number of cards named Power Pylon.

Context: A set that has a faction with an artifact subtheme. around 15% of creatures are artifacts. Thoughts?

It's hard to gauge the actual power level of the "any number of cards" ability. Obviously, decks based on Relentless Rats, Rat Colony, and Persistent Petitioners have competed at various levels, but part of the strength of those cards is that they are exponential - they're creatures unto themselves and every time you play another each of them gets bigger or stronger in some fashion. With that in mind, this card doesn't have quite that level of explosive growth, but also it's not as vulnerable to a wrath (you're not starting from square one if you have to play creatures to an empty board) and is more flexible.

I might lean towards this card costing 1 more but that might be too underpowered. The deciding factor is: You obviously can't build a deck solely of this card and lands.

If that helps, the card would actually cost {u/r}{b/g}. Do you think I should include a high cost sac ability or is it fine as-is?

A more restrictive mana cost makes it fine for sure imo. If you want something extra, maybe "7, T, Sacrifice this: Lightning Bolt"

Another, related idea: Unlimited Wretched Throng, possibly costing 3mana?