Help me with my custom Warlock patron

I've been playing D&D for around three years now, and we have a collective worldbuilding system in our group where we all get to DM a mini-campaign before switching back to being a player. Although it isn't mandatory, the idea is to keep your character and let them grow and level up throughout the mini-campaigns (if they survive).

For my campaign, I created a custom, astral-themed patron at the request of one of my players to fit their character's background (an Elf Warlock).

For the next mini-campaign, the new DM will adapt my patron and continue their ambitions for this Warlock, who will be level 6. I've attached the information I have so far, and I would love for you to suggest abilities, spells for each level and/or general ideas. I've never played as a Warlock myself, so I'm sure you have some great ideas. Any suggestions?

Info about the patron so far:

Equuleus was once an ambitious alchemist specialising in the 11th step "lossless multiplication" of the 12 core processes that make up the Great Work, the Magnum Opus. Equuleus' ambitions exceeded both their own beliefs and those of their fellow alchemists, revealing to the astral gods a talent for seeing what most eyes cannot. Equuleus became a renowned and gifted foreseer who shared their visions with the celestial gods.

Upon foreseeing their own victory over the gods, Equuleus was met with wrath and punished with banishment, cast into a black hole. They were granted grace in the form of a star to guide and comfort them on their descent into the endless singularity. Squeezed into an endless void, a black hole that sucked up and compressed everything into a singularity, they found themselves contained within it. Time and space no longer mattered; only unity, compressed into one, remained - their essence, or soul, endlessly fed and fermented by everything the void could draw in.

An understanding was born. Everything orbiting the black hole would, in time, be compressed into the very singularity of which Equuleus was a part of. Therefore, Equuleus and all the particles that would inevitably fall into the black hole's singularity were one and the same - even time itself. And since everything was one and the same, Equuleus learned to materialise from matter and time beyond the black hole, from that which had not yet succumbed to its pull. Thus, Hadi, the star-born foal, came into being: an extension and companion of Equuleus, to accompany them out of the unending darkness. Through stars and particles doomed to eventually fall into the singularity, Equuleus began to travel once more, inhabiting and linking his stars as their new, temporary home.

And so, Equuleus emerged once more, wielding powers born of their newfound understanding of the unusual coalescence of the void and the stars. Drawing upon their visionary and obscure abilities, they shared their knowledge with those willing to learn. In return, these scholars would help Equuleus fulfill their vision: to bring down the astral gods and realize their original ambition. They would achieve triumph even though Equuleus was doomed to eventually fall back into the endless void. Their victory would outlive them all, enduring as the most vibrant constellation that outshone all others - a brilliant astral remembrance.

Goal
As Heinrich Cornelius Agrippa stated: like begets like (similar things produce or cause similar things). Equuleus seeks like-minded individuals to guide and help them become like Equuleus themselves. These individuals are, in essence, already like them and are therefore destined to become “the same”. That is the very foundation of their understanding of lossless multiplication. They must be guided towards this understanding and linked together. These linked individuals form Equuleus, a faint constellation meaning “little horse” or “foal”, located just north of the celestial equator and growing increasingly brighter.

Ultimately, Equuleus seeks to fulfill their vision of victory over the gods and astral cities. This vision remains unchanged, and Equuleus understands that they must multiply and grow in power to achieve it.

Maybe a Vestige patron? The horse companion seems to fit with Vestige being a pet summoning class.

Or perhaps Celestial, with the Radiant damage being from the stars?

I've also never played a Warlock, but that's what comes to mind based off your description.

That sounds great! I thought about Celestial as well before and it works to some degree but I didn't know about the Vestige patron yet so I just looked it up - it fits perfectly!

Thank you very much for your suggestion.