Eberron Warlock
There’s no such thing as a typical warlock. If it was easy to make a pact, everyone would do it. Some warlocks might have gained power through sheer luck, just happening to be in the right place at the right time, when the moons and planes aligned over a particular manifest zone, allowing a deal to be struck with an extraplanar being. While other warlocks may have earned their pact through research and effort, learning long-forgotten rituals to conjure and negotiate with the patron. A warlock could be a member of a bloodline with ancestral ties to a fiend, or they might have claimed an artifact in a forgotten ruin. It’s up to the player and DM to decide how the pact was made, but always remember that every warlock is remarkable. This sort of arcane power doesn’t come easily, and every warlock should have a story. Morgrave Miscellany, page 77, gives examples of what playing a Warlock in Eberron might look like.
In addition to the subclass options presented on dndbeyond, the following Warlock Patrons are also available:
The Daughters of Sora Kell
The driving force behind the rise of the monstrous nation of Droaam is the trio of powerful hags who rule it. Known as the Daughters of Sora Kell, this powerful coven has been elevated to an otherwoldly level of power by the visions of one of its members, the ancient Sora Teraza. Though she is said to be the greatest seer and diviner in Eberron, Sora Teraza has a tenuous grasp on reality and mysterious motives, which often blur the line between manipulation, prophecy, and madness. The more worldly abilities of her coven sisters - the green hag who acts as the voice, leader, and strategist of the group, Sora Katra, and the more direct military leader and enforcer, the annis hag Sora Maenya - have helped accumulate a large group of loyal ogres, trolls, and the like, fanatical followers who would die for their queens. Aside from the residents of Droaam, few ever seek a pact with these all-seeing hags - their dealings occur in times and places of their own choosing, at moments in time when great destinies intertwine or unravel. Most of their warlocks are goblins, bugbears, kobolds, and the like, but they are patrons of many carefully selected members of other races as well. Few of those the Daughters choose to approach with a pact can elude their occult manipulations for long.
Just as a coven of hags employs both fey and fiendish powers, the Pact of the Daughters of Dora Kell combines abilities reminiscent of the Pacts of the Archfey and the Fiend with a glimpse into Sora Teraza's nearly infallible prescience.
- Source: Eberron Archetypes, page 44
The Dragon Below
Is Khyber truly a titanic dragon? A realm of madness and darkness? In either case, Warlocks who enter a pact with the Dragon Below are a rare breed. Few have the capability to successfully seek out the entity, let alone strike up a bargain with the potent and legendary force. Those who do so and survive gain incredible power which enables them to act as an extension of Khyber’s mad will.
Warlocks of Khyber are gifted with the ability to summon minions to serve them and act as disposable assets in their dark pursuits. While this grants the warlock great potency it is also indicative of the relationship the warlock enjoys with her patron. A warlock of Khyber is little more than an expendable asset to the Dragon Below
- Source: Faithful of Eberron, page 54
The Transcendent Machine
A great machine houses the consciousness that holds your pact, rather than flesh or spirit. This not only gives you an innate understanding of magical engineering, but intertwines your destiny with Daanvi, the plane of Perfect Order. Your patron may be a divine spark manifesting with the Becoming God, the massive scavenged sculpture being built by warforged pilgrims in the Mournland. It may be a poten eldritch machine with its own innate intelligence, or one tied to the incarnation of living souls, like a creation forge. It could also be a powerful entity ruling Daavi's native modrons or formians, or a greater servant of the god Onatar. There are even rumors in Sharn of a trio of warlocks who draw their magic from an emergent mind with Khorvaire's lightning rail network.
Like all machines, the source of your pact exists for a larger purpose, yet despite its lawful nature, its agenda is not always easy to discern. Yet somehow, its reach extends through the planes to you. While you may not share your patron's goals or alignment, it has chosen you to play a role in some grand cosmic plan.
- Source: Eberron Archetypes, page 46