Arcane Signet

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

Kudo, King Among Bears

Other creatures have base power and toughness 2/2 and are Bears in addition to their other types.

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.