Perrie, the Pulverizer

When Perrie enters, put a shield counter on target creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Whenever Perrie attacks, target creature you control gains trample and gets +X/+X until end of turn, where X is the number of different kinds of counters among permanents you control.

Contractual Safeguard

Addendum — If you cast this spell during your main phase, put a shield counter on a creature you control. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Choose a kind of counter on a creature you control. Put a counter of that kind on each other creature you control.

Brokers Veteran

When Brokers Veteran dies, put a shield counter on target creature you control. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Boon of Safety

Put a shield counter on target creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Scry 1.

Dapper Shieldmate

Dapper Shieldmate enters with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
During your turn, Dapper Shieldmate gets +2/+0.

Falco Spara, Pactweaver

Flying, trample
Falco Spara, Pactweaver enters with a shield counter on it.
You may look at the top card of your library any time.
You may cast spells from the top of your library by removing a counter from a creature you control in addition to paying their other costs.