Thrummingbirds Thrummingbird was the original repeat-proliferator that triggered on combat damage, though Grateful Apparition, Guildpact Informant, Bloated Contaminator, and Vexing Radgull among a few others have joined the ranks
Also, it can nab a Portal to Phyrexia if you need it to
It produces lots of creatures but rather than buff them and go face this deck will consume those creatures and gain advantages from triggers when they die, the things making them die and even triggers when they come into play
Skyclave Relic AND Everflowing Chalice The Relic is awesome since base it's just a mana rock with indestructible with three mana kicker for two copies, so it's a better Darksteel Ingot
If you wanted to tune this up, the first place to start would be to run a different commander and then focusing the list around what that legend brings to the party