Aragorn, Hornburg Hero

Attacking creatures you control have first strike and renown 1. (When a creature with renown 1 deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever a renowned creature you control deals combat damage to a player, double the number of +1/+1 counters on it.

Command Tower

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

Arcane Signet

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.