Lightning Bolt would still be one of reds best spells with that restriction, and this card is better
Ashad, The Lone Cyberman (Artifact Copy) Ashad, The Lone Cyberman is a solid commander built around artifacts and sacrifice
No back-up strategy, just kill, kill, kill
For example, searching "add three mana" returns cards containing this text block like Black Lotus , Lotus Vale , Gilded Lotus
The key here is that Byrke, Long Ear of the Law doesn't have to be the creature attacking, so you can get double counters on two attackers the turn Burke enters, and it gets out of hand on subsequent turns
All this combined makes it impossible to make a "bad" Sauron deck since he brings so much value on his own, but we can definitely raise the power ceiling by making an optimized brew