Enter your shell as an action, gaining +4 AC, advantage on Strength and Constitution saving throws, and resistance to poison damage. You become prone and your speed becomes 0 until you emerge as a bonus action.

Use your reaction and expend a Bardic Inspiration die to subtract the die result from a creature's attack roll, ability check, or damage roll.

You gain proficiency in three additional skills of your choice. When a creature you can see within 60 feet makes an attack roll, ability check, or damage roll, you can use your reaction to expend one Bardic Inspiration die and subtract the result from the roll.

Add a d8 to a willing creature's ability check, attack roll, or saving throw after it rolls but before the outcome is determined.

You can inspire others through stirring words or music. A creature within 60 feet that can hear you gains one Bardic Inspiration die, a d8, usable on one ability check, attack roll, or saving throw within the next 10 minutes. You can use this feature five times per long rest because of your level and Charisma modifier, minimum one use.

You can add half your proficiency bonus, rounded down, to any ability check you make that does not already include your proficiency bonus.

You can use music or oration to restore vitality during a short rest. Friendly creatures who hear your performance regain an extra 1d6 hit points when spending Hit Dice.

You can use a musical instrument as a spellcasting focus. You learn three cantrips and know eight bard spells. Charisma is your spellcasting ability.

You gain one additional use of Bardic Inspiration, for a total of five uses per long rest.

You gain an Ability Score Improvement. This character uses it to increase Intelligence from 15 to 16, already reflected in the listed ability scores.

You have a false identity, complete with documentation, established acquaintances, and disguises that allow you to pass yourself off as another person. You can also forge documents and impersonate people well enough to deceive ordinary observers.