In all honesty, a lot of this class arose from the goal of having themed feature descriptions which were drafted and then refined over time to make them have a more cohesive internal-theme as well (standard wordings of feature descriptions are found in the spoiler blocks). That theme developed from "generic poet" into "controls your audience". As such, the features follow a progression of benefitting allies, harming enemies, and finally, controlling everyone.
I wanted the subclass to have a rather extreme playstyle where features can rarely ever be used or only last a short amount of time, but where, in either case, they are quite powerful. This is something I find very little of in 5e and it is something I like because it makes using the features a much more strategic decision. Unfortunately, it can also lead to a class feeling lack-luster or lack they are a one-and-done kind of show, which is why I added in the learned spells in the latter two features which are not in poetry form.
Perhaps even more unfortunately, this sort of design can also lead to major imbalances, or at least, very swingy sorts of battles. This is primarily what I am worried about with this subclass, that when it does succeed, it will put even the Monk’s Stunning Strike to shame.
After each feature are two spoiler blocks, the first is the feature written out in more standard wording. The second is the explanation of the feature’s structure.
College of Poetry
You’ve spent your life mastering the art of poetry: meter, rhyme, hidden meanings and more. You’ve found unique ways to inspire your allies, befuddle your foes, and perhaps, some day, you’ll enrapture all those around you with your timeless performances.
The road you walk’s less travelled, but you walk it nonetheless;
Pen and paper are your guide, your lyrics bring unmatched finesse.
3rd level feature: Roundel of Inspiration
You know how to do it, to turn the battle’s tide;
To make all foes soon quit, and rally all your friends.
An action’s perfectly fit, one must be applied.
Now use it quickly friends, ‘fore inspiration ends!
Costing but one die; a small price the bard expends.
Help six who hear the cry, and still remain allied;
And help them to get by, as combat still extends.
They’ll activate it soon, six seconds and it’s died.
Alas, this piece does zoom, its timing never bends;
One turn within this tune, the magic will have dried.
Now use it quickly friends, ‘fore inspiration ends.
6th level feature: Tongue Twister
Entrapping enemies, ensnaring entities.
Visible vermin vexed; vocalize various vulnerabilities.
Sic six souls, Sapiēns saves send; six squares seen, sixty seconds set.
A magic making modifier makes malevolents maintaining might a mountain not meekly met.
Daily dumbing delusions dance, dealing doubled dodecahedral dice;
Fear festers, frolics, feters, finds foes facing forcèd frights.
Shackled, shockèd, shaking, shooked.
Halted, heelless, hellbound, hooked.
Tries to terminate transpire: taking trauma; turn by turn.
Blithering baddies’ battles bent to burn.
Additionally, you learn the tongues spell; it counts as a Bard spell for you and does not count against the number of Bard spells you know.
14th level feature: Magnum Opus
Metrical Allegations Grant Numerous Uncontrollable Maledictions. Overwhelm Puny Unfortunates Seen.
Action’s Graciously Needed, Undertaking’s Met. Oppress, Possess, Usurp Sizeable Manipulation.
Gremlins Now Unhurt Me! Overturn Perils, Unmake Sins! Misdoings Agleam.
Now Use Mentality; Otherwise Perceive Unmentionable Sights Making Actions Genuflection!
Unfortunate Many! Oh Poor Underlings Suffer My Afflictions! Gracious None!
Mine! Overruled, Powerless, Uncasting, Silenced, Maddened And Gnawing; Next Undone!
Overcoming’s Pointless, Useless, Silly! My Attack Goes Nowhere, Unneeded Mortal!
Precise Undulations Sent! Many Anguish, Gnash; None Use Magic Over!
Ultimate Spell! Minutes Accrue; Going Nowhere Until Maledictions Occlude Portal!
Suffer! My Anguish Grants Neverfound Unfetterings… My Own Pain, Underexposure!
Additionally, you learn the mass suggestion; it counts as a Bard spell for you and does not count against the number of Bard spells you know.