You bend your ear toward strange stories of fantastic rituals and ancient magics and have been inspired by those who dabble with such strange power. Whenever you learn a new bard spell, you can choose instead to learn an Eldritch Invocation, per the Warlock feature. This invocation (and any spell or ability it grants you) counts as a bard spell for you and is treated normally as one of your spells known but does not count as one of the special spells you gain with the Magical Secrets class features. If an Invocation has a level prerequisite, you use your Bard level to determine if you meet it. Otherwise, whenever you use the Invocation, you must expend a use of your Bardic Inspiration and, once you've used it, you must complete a short or long rest before using it again. If the Invocation allows you to cast a spell with a warlock spell slot, you must expend a bard spell slot of equal level in addition to a use of your Bardic Inspiration. You must abide by any rules or limitations imposed by the Invocation. Once you have used this ability, you must complete a short or long rest before using it again.