Base Class: Bard
This bard college focuses on honing Vicious Mockery and Guidance.
Scathing Review
When taking this subclass at 3rd level, you gain the Vicious Mockery and Guidance cantrips. The damage die of Vicious Mockery becomes your Bardic Inspiration die. In addition, you may add your Charisma modifier to the damage when the spell's target fails its save.
Finally, when casting guidance, the spell may be used on any number of ability checks within the spell's duration as long as concentration is maintained.
Critical Eye
Whenever a creature you can see within 60' of you misses with an attack, you gain a special reaction which can only be used to cast vicious mockery against the creature that missed. You can use this reaction multiple times when it is granted by subsequent misses up to a number of times equal to your proficiency bonus per round, but once it is used you may not use any other reaction until the start of your next turn.
Staggering Words
You can cause a creature that fails a save against your vicious mockery to use its movement to immediately stagger 5' in a direction of your choice, or fall prone. Any movement spent in this way is lost until the end of that creature's next turn. A creature that is already prone loses 10' of movement until the end of its next turn. A creature with a move of 0 cannot be made to stagger, but can still fall prone.
In addition, a creature under the effect of your Guidance spell gains +1 to its proficiency bonus until the spell ends.