Armguard Familiar

Ward 2 (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 2.)
Equipped creature gets +2/+1 and has ward 2.
Reconfigure 4 (4: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn’t a creature.)