From Sorcerer Supreme #004

Art by Bernard Chang, Ruth Redmond, Erick Arciniega and Rod Fernandes

Wanda's been targeted in the past by devotees of Set and wearers of the Serpent Crown, so he's definitely aware of her, and since she and her allies have thwarted his plans in the past, I doubt he's a fan. I personally think that Mystic Arcana: Scarlet Witch sucks and is only dubiously canon, but if we take it at face value, we can infer that Set knows Chthon had laid claim to Wanda, as it were. I assume he thinks of her as little more than an avatar or pawn of his brother's.

I don't think Wanda's ever had any direct interactions with Oshtur or Gaea*, although it's possible I'm forgetting something. Both goddesses, I think, generally oppose Chthon and would likely support Wanda as a victim who has overcome him on multiple occasions. But both goddesses, particularly in modern comics, have also proven themselves to be somewhat morally ambiguous, and they both tend to act in the interests of a much larger picture. If I had to guess, I'd say that they're both aware of the potential threat that Wanda poses to the natural order of things, as they see it, and would be just as likely to move against her if they deemed it necessary. I think their perspectives, in this regard, are probably quite similar to the Griever's, although neither of them are quite as fanatical.

In Contest of Chaos, it became clear that Wanda's binding of Chthon and the Darkhold had upset the balance of Earth's natural chaos magic. I'd assume that Gaea and Oshtur would want to get that under control as quickly as possible, but they didn't come up in the story. Now that Chthon has escaped, I assume that Wanda will need to seek a more sustainable solution, so maybe we'll hear more from them in the future. I'd certainly be very interested, although between the current Immortal Thor storyline and whatever is going on with Doom as Sorcerer Supreme, they've both got their hands full.

A preview of Doctor Strange #12

DOCTOR STRANGE #12

Doctor Strange is a busy man—sometimes, it seems like the busiest man. But that man has a best friend. So when there’s something strange haunting the Sanctum Sanctorum, who can we turn to? Why, BATS THE GHOST DOG, of course! But can Bats solve the mystery on his own, or is this good dog in over his head?

LEGACY #438

Thor Annual #10 (1982): In a primal time many eons ago when the Earth was still forming, the Demiurge (the incarnation of the power of creation) arose from the crackling energy of the planet's nascent biosphere!

Silver Surfer Annual #2 (1989): The Demiurge seeded the newborn planet with its energies, giving rise to Earth's Elder Gods: Gaea (Mother Nature), the dark mystic Chthon, the serpentine Set, and the sorceress Oshtur!

Thor Annual #10 (1982): However, when most of the other Elder Gods degenerated into demonic beings and began to destroy each other, the benevolent Gaea convinced the Demiurge to help her create Atum, the first of a new generation of gods!

Silver Surfer Annual #2 (1988): Atum attacked the demonic Elder Gods and absorbed their corrupted life forces, transforming him into the monstrous Demogorge!

Thor Annual #10 (1982): After all of the demonic Elder Gods had either been destroyed or chased into other dimensions by the Demogorge, he purged the corrupted god energies from his body and reverted back to his Atum form, eventually retreating into Earth's sun.

The History of the Marvel Universe #1 (2019): This god energy fell back to the Earth, where the nascent consciousness of mankind eventually tapped into it, giving rise to new pantheons of gods born in man's image.

Greetings and thanks for asking!

1) The Elder Gods are deities conceived by fragments of the Demiurge’s essence, even before humanity. The Vishanti is sort of a holy trinity made by three deities: Oshtur, Hoggoth and Agamotto. Oshtur is considered an Elder God. Stephen’s magic comes from many, many, many deities, including the Vishanti and Gaea. Usually, they don’t really care about mortals but Stephen is different. He’s powerful and has a noble heart, that’s why his services were requested by them during the War of the Seven Spheres. Concerning Gaea, she's Earth’s spirit. Many times she was in jeopardy because of magic, and Stephen has always come to her aid. Once he even used her powers when he lost the mantle of Sorcerer Supreme to Salomé. She also considers Stephen special. I don’t recall if Stephen has ever met Chthon personally, but Set? Definitely. He first met the Crown Serpent during a team-up with the Thing, Scarlet Witch and Spider-man, and then with Thor, Quasar and the Thing again. Stephen only read about Chthon while he was researching the Darkhold, I believe (but he met Chthon in Super Hero Squad and it’s super funny, this show is priceless). Also, Stephen is “closer” to Agamotto because of his Alice-in-Wonderland-version back in Master of the Mystic Arts and Sorcerer Supreme, but Agamotto is kind of a jerk according to these stories. As I said, most deities don’t even care about humanity, they simply exist and lend their powers. Stephen is close to them because he’s that special. The Living Tribunal and Eternity share a certain bit of history with him, and those entities are quite above the Elder Gods. I love Stephen.

2) Bendis is... complicated. In What If? Avengers Dissambled, Stephen said that he never told the Avengers chaos magic doesn’t exist. It was an illusion spell made by Wanda. He’s aware that it exists. Bendis was probably on drugs that day and he also hated Wanda. Please, ignore it. Also, no, Stephen remembers most of his encounters with Set, Eternity, The Living Tribunal, Gaea and so on. Usually, he’s one of the few people who remember the most important events in Marvel’s history.

3) Entities do exist in the MCU. They were mentioned by the sorcerers in Doctor Strange when they named the artifacts. Wong uses the Wand of Watoomb and Mordo wears the Boots of Balthakk. The Eye of Agamotto is another important artifact that makes reference to the Vishanti, including Oshtur. Lastly, Cagliostro was another powerful sorcerer who evolved to a god-like status. Oh, and don’t forget Dormammu. Also, they don’t chant most of their spells, but whenever you see Crimson Bands of Cyttorak or Images of Ikonn or the Shield of the Seraphim, they’re drawing powers from those entities. The problem is, entities are just too powerful and a hard concept to viewers, not to mention that magic is pretty neglected in the MCU. Even in comics, sorcerers and people touched by the supernatural are usually the only ones who have knowledge about them due to their personal experiences.

Got ya’ covered

So, I don’t read the comics, but I have done some research about the Vishanti in the past for the purpose of fic writing, so I feel like I have a fairly solid idea of what they are. 

The Vishanti are a triad of god-like, extra-dimensional beings that exist in the Marvel universe. There’s Hoggoth, Oshtur (who I now realize I have been misspelling the name of ... sorry, I guess I just thought Oshun sounded better), and Agamotto, whose name you may recognize from the Eye of Agamotto that held the Time Stone in the mcu and allowed someone to manipulate time. They’re usually benevolent, and protect the earth as well as giving aid, knowledge, and magic to the sorcerers, especially the Sorcerer Supreme.

There’s a bit of mythology about them, starting with Oshtur (who seems to be female-coded or gendered) leaving her home amongst the Elder gods of Earth to wander the universe. She met Hoggoth, whose own people were otherwise extinct, and they decided to travel together. 

One day, Oshtur saw three children playing, and was so moved by their joy/vulnerability that she shed a tear, which Agamotto appeared from, making him her son in a fashion.

Agamotto seems to be the most directly involved with humanity, being the first Sorcerer Supreme, appearing in a somewhat human form (although he does have significantly less human forms, like a lion or tiger, although the other two, especially Oshtur, primarily appear as humans), and even joined a stone-age version of the Avengers. Part of this is out of necessity since Oshtur is bound to non-interference against certain entities, so Agamotto handles it instead.

So far in the MCU, only Agamotto has been mentioned, with Wong stating that he (or some version of him at least) is the father of the mystic arts and created the Eye of Agamotto as well as the three Sanctum Sanctorums. Hopefully we’ll see more of them in the future, but who knows.