Warning: This article contains spoilers for Powers of X #4, by Jonathan Hickman, R.B. Silva, Marte Gracia, VC's Clayton Cowles and Tom Muller, on sale now.

Mister Sinister knows a lot of secrets, especially because the X-Men villain has conducted his twisted genetic experiments on the fringes of the Marvel Universe for more than a century. And more than any other Marvel series in memory, Powers of X and House of X have been built around the idea of the secret knowledge -- that gathered by Moira MacTaggert over her numerous lives and reincarnations.

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When Charles Xavier and Magneto use that knowledge to encourage Sinister's research on mutants in Powers of X #4, they find the villain at Bar Sinister, an island base comprised entirely of Sinister clones. Immediately following that meeting, Powers of X features an excerpt from The Red Diamond, which keeps Sinister's clones up to date on the latest gossip, with "Sinister Secrets."

However, unlike most real world tabloids, this newsletter teases the X-Men's future with blind items that have deep ties to the X-Men's history and current adventures. Now, CBR is breaking these down to see what Sinister's Secrets may say about the Marvel Universe.

MISS SINISTER'S RETURN?

Miss Sinister Art Adams

The first Sinister Secret mentions a Sinister trying to hide their wearing red shows. From the fairy tales to the Ruby Slippers of Wizard of Oz, red shoes are linked to femininity in popular culture. With that in mind, this item is most likely a reference to Miss Sinister, Mister Sinister's female counterpart, who was created by Mike Carey and Scott Eaton in 2008's X-Men: Legacy #214.

After Mister Sinister seemingly died, he lived on through a virus that gave Claudine Renko his personality and powers. While she's conducted her own twisted research, she's never been totally on the same page as Sinister and may be quietly plotting on Bar Sinister.

A LEADER REBORN?

House of X Cyclops

The second Sinister Secret refers to "a trendsetting mutant who was cut down in his prime" and is set to become a prominent mutant, which could apply to a few dozen characters. However, the item's tease also urges mutants "to stop wearing human clothes," which may be a reference to Cyclops.

RELATED: A House of X Death Mirrors the Phoenix's Original Demise

After the X-Men wore black, relatively realistic leather ensembles in New X-Men era, Cyclops famously ordered the team back into superhero costumes at the start of the Astonishing X-Men era to help their public image. Even though he was just killed in House of X #4, Cyclops set a trend by being the first mutant to join the X-Men and seems set to return to his traditional leadership role soon.

MADELYNE PRYOR'S SECRETS

Madelyne Pryor as Inferno

After Jean Grey was thought dead in the wake of the iconic "Dark Phoenix Saga," Sinister created Madelyne Pryor, a clone of her that was given life by a spark of the Phoenix Force. In the 80s, Pryor befriended the X-Men, married Cyclops, and made a demonic deal that turned her into the evil Goblin Queen.

The third Sinister Secret seemingly references Pryor by identifying her as "a red-headed pretender" who made a deal with the devil. The item goes on to suggest that Sinister knows the secrets she died with and that she left something else behind, which could be an arcane artifact or some small piece of the Phoenix.

WHAT WASHED ASHORE

Invaders header

Despite their massive revelations, House of X and Powers of X have been largely divorced from the rest of the Marvel Universe. However, the fourth Sinister Secret warns of "what washed ashore," which may be a threat from an increasingly aggressive Namor the Sub-Mariner, Marvel's King of Atlantis.

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In Invaders and Avengers, Namor has declared war on the surface world for its crimes against the Earth's oceans. Even though he was once an X-Man, Namor probably isn't be too happy about Xavier using the mutant island Krakoa to establish a new surface-world country in the middle of the ocean and may already be sending warnings through the tides.

THUNDERBIRD'S LEGACY REVEALED

thunderbird chaos war

Earlier in the issue, Sinister reveals that he created a clone of himself using a mystery mutant's DNA. Just page after he usurps his human counterpart, The Red Diamond reveals that this Sinister was created with DNA from John Proudstar, Thunderbird.

Along with heroes like Wolverine and Storm, Proudstar joined the team in Len Wein and Dave Cockrum's Giant-Size X-Men #1. However, he died on his next mission with the team. While his legacy has lived on through his brother James, the X-Men's Warpath, this revelation adds another layer of tragedy to a hero's journey that was tragically short.

X-MEN LOVE TRIANGLES

X-Men Love Triangles

Outside of Archie Comics, the X-Men have some of the most famous love triangles in comics, and the fifth Sinister Secret essentially confirms their return. While Cyclops and Jean Grey have a decades-long relationship that culminated in their marriage and alternate-reality children, both heroes are just as famous for seeing other people.

RELATED: X-Men Finally Gives Marvel Fans the Reunion They've Been Waiting For

Jean Grey has had a very well-documented romantic attraction to and flirtation with Wolverine, and Cyclops had a flirtation with Emma Frost that blossomed into a full-blown relationship. While death has torn these pairings apart in recent years, this item suggests that these triangles may reform before long.

STRYFE'S LEGACY

Stryfe X-Cutioner's Song

One of Mister Sinister's former allies was the X-Men villain Stryfe, a progerian clone of Cable who was artificially aged up to adulthood. While his direct efforts against the X-Men weren't too successful, Stryfe tricked Sinister into unsealing samples of the Legacy Virus, a mutant plague from the far future that ravaged the mutant community in '90s X-Men comics.

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Although the late-'90s efforts of Moira and Colossus seemingly cured the Legacy Virus worldwide, the sixth Sinister Secret seems to indicate that Sinister may still have some samples of the Legacy Virus, or perhaps the genetic material that Stryfe originally promised him.

THE SUMMERS BROTHERS

X-Men 1 Leinil Yu Summers Family

In one of the famous X-Men sub-plots of the'90s, Mister Sinister teased Cyclops about having multiple brothers. While Cyclops and his brother Havok grew up together before reuniting in the X-Men, the identity of the possible third Summers brother was teased and debated by fans for years.

In Ed Brubaker and Trevor Hairsine's X-Men: Deadly Genesis that brother was eventually revealed to be Vulcan, a long-lost X-Man who became a powerful intergalactic tyrant. The seventh Sinister Secret claims that there could be even more Summers brothers out there, which may have something to do with the presence of the entire Summers family on Leinil Yu's upcoming cover to X-Men #1.

APOCALYPSE'S FIRST HORSEMEN

Apocalypse First Horsemen

In his seemingly endless quest to build a world around the idea of the survival of the fittest, Apocalypse has relied on his Four Horsemen to carry out his will. The Horsemen's rotating roster has included everyone from Archangel to Wolverine, and the eighth Sinister Secret indicates that Apocalypse's original Horsemen will be making a return.

Unlike the other entries in The Red Diamond, this already started in Hickman and Dustin Weaver's story from Marvel Comics #1000, where Apocalypse said that no Horsemen were as good as his first and began resurrecting them.

MOIRA AND APOCALYPSE?

Apocalypse Moira Powers of X House of X

The ninth Sinister Secret calls out a "non-couple couple" that has been separated for a long time and could have a universe-shaking reunion. While that could refer to a few different X-Man pairings, it's most likely a reference to Moira MacTaggert and Apocalypse, who were a couple in Moira's last life.

RELATED: How Powers of X Ties Apocalypse and Moira Together

Having exhausted her other options in the ninth of her 10 or 11 lives, Moira shunned Xavier and Magneto and tried to save the future for mutants by allying herself with Apocalypse. As early preview artwork for Powers of X teased, that couple may reunite in the very near future.

A NEW INFERNO?

X-Men Inferno

In the world of the X-Men, the word "Inferno" holds a special meaning. In the late '80s, Mister Sinister and Madelyne Pryor enacted the ultimate plans against the X-Men and unleashed a demonic invasion in New York in the seminal Inferno crossover.

While that story cemented Sinister as an A-list X-villain, this entry in The Red Diamond simply states that something that took a long time to build can be destroyed quickly, as if engulfed by an inferno's flames. Since Xavier and Moira are in the midst of carrying out long-established plans, that ominous warning doesn't bode well for them.

SINISTER'S HOUSE OF X

Mister-Sinister

After Xavier and Magneto successfully compelled Sinister to focus his research to mutants, Xavier tried to telepathically make Sinister forget about their meeting until an unspecified later date. However, the tenth Sinister Secret establishes that Sinister didn't exactly do what he was told.

Instead of forgetting about Xavier's visit, he was replaced by a clone of himself who remembered Xavier's visit. Additionally, he seemingly knew about Xavier's larger House of X plans long before they were implemented. While it's not clear how Sinister will twist that knowledge to his advantage, the villain seems set to play a crucial role as House of X and Powers of X approach their shared ending.

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