Idolized

Enchant creature
Enchanted creature has "Whenever this creature attacks alone, it gets +X/+X until end of turn, where X is the number of nonland permanents you control."

Sol Ring

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Forest

Dogmeat, Ever Loyal

When Dogmeat enters, mill five cards, then return an Aura or Equipment card from your graveyard to your hand.
Whenever a creature you control that's enchanted or equipped attacks, create a Junk token. (It's an artifact with "{T}, Sacrifice this artifact: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.")

Armory Paladin

Trample
Whenever you cast an Aura or Equipment spell, exile the top card of your library. You may play that card until the end of your next turn.

Plains

Mountain

Inventory Management

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
For each Aura and Equipment you control, you may attach it to a creature you control.