Trickery Clerics get this Channel Divinity option: Invoke Duplicity.
... As an action, you create a perfect illusion of yourself that lasts for 1 minute, or until you lose your concentration (as if you were concentrating on a spell). The illusion appears in an unoccupied space that you can see within 30 feet of you. ... it must remain within 120 feet of you. For the duration, you can cast spells as though you were in the illusion's space, but you must use your own senses. Additionally, when both you and your illusion are within 5 feet of a creature that can see the illusion, you have advantage on attack rolls against that creature, given how distracting the illusion is to the target.
This upgrades at 17th level: Improved Duplicity.
... you can create up to four duplicates of yourself, instead of one, when you use Invoke Duplicity. As a bonus action on your turn, you can move any number of them up to 30 feet, to a maximum range of 120 feet.
How does spellcasting interact with Improved Duplicity? In other words, could the spell originate from multiple (perhaps all four) duplicities at the same time, or from only one?