Rubinia Soulsinger

You may choose not to untap Rubinia Soulsinger during your untap step.
{T}: Gain control of target creature for as long as you control Rubinia and Rubinia remains tapped.

Lagrella, the Magpie

When Lagrella, the Magpie enters, exile any number of other target creatures controlled by different players until Lagrella leaves the battlefield. When an exiled card enters under your control this way, put two +1/+1 counters on it.

Grand Arbiter Augustin IV

White spells you cast cost {1} less to cast.
Blue spells you cast cost {1} less to cast.
Spells your opponents cast cost {1} more to cast.

Stoic Angel

Flying, vigilance
Players can't untap more than one creature during their untap steps.