Ring of Fortitude

Equip {3}
Equipped creature has indestructible and can't
be exiled
Equipped creature has "{t}: add three mana of
any color(s) to your mana pool"
Monks you control have +2/+3 and Martial Arts
(When this creature blocks or is blocked by a creature without Martial Arts, blocked or blocking creature has
-2/-2 until end of turn.)