Sebastian Baelmont, Sage

Whenever another creature you control becomes the target of a spell or ability you control, put a shield counter on it.
{1}{w}{u}: Distribute two +1/+1 counters among up to two target creatures. If you control a creature with a shield counter, you may instead distribute three +1/+1 counters among up to three target creatures.
{2}{w}, {t}: Sebastian Baelmont, Sage, deals X damage to target tapped creature, where X is the number of creatures you control with shield counters.