Decades ago, a powerful psychic mutant named Charles Xavier decided to make a place where his kind could be safe. Charles turned his ancestral home into Xavier's School for Gifted Youngsters. Soon afterward, he took thousands of mutants from around the world under his wing. Prof. Xavier taught these men and women how to control their primary mutant powers, and the rest is history.

Primary mutations are the first powers a mutant develops. Secondary mutations come later in life - either naturally or artificially. Today, we're going to discuss 5 secondary mutant powers that are very powerful and 5 that aren't so great.

RELATED: MCU Phase 4: 5 Rumored Characters We Want To See (& 5 We're Not Sure About)

10 10. Weaker: Beast's Feline Form

It's kind of funny how one of the weaker secondary mutations is also one of the most well known. Beast, born Henry McCoy, is an OG; he was part of Xavier's first class of mutants and a founding member of the X-Men. Most people recognize Beast as a guy who resembles a giant blue cat. Well, Hank's most iconic look is actually his secondary mutation!

Hank first developed an array of bestial traits during adolescence. This primary mutation made Beast stronger, faster, and more dextrous than the average man. Later in life, a mutant named Sage jump-started Hank's 'latent genetic potential.' As a result, he resembled a blue cat for many years.

9 9. Stronger: Emma Frost's Diamond Skin

Bullets bounce off of Emma Frost's face while she's in diamond form

Emma Frost is another popular X-Men with an iconic appearance. Frost's diamond-like skin is one of her most distinguishing characteristics. Best of all, it isn't just for show - Emma's diamond form drastically improves her defenses! Furthermore, Emma's children also possess the ability to transform into a diamond state. Despite how often Emma uses this ability, it's not her first mutation.

RELATED: 'X-Men' fans give Emma Frost an overdue fashion makeover

Emma Frost is a psychic at her core. Her psionic might is so great that she attracts the Phoenix Force, just like Jean Grey. Emma didn't gain her diamond skin ability until she was attacked by Sentinels. Her secondary mutation kicked in a saved her from otherwise certain death.

8 8. Weaker: The Blob's Stretching Powers

Blob Deadpool

Frederick Dukes isn't a smart man. Nor is he a good man, for that matter. But he's tough as nails, big as a house, and short-tempered. Fred was born with a bad attitude, but he gained the other two abilities around puberty. From that point on, Fred started calling himself the Blob.

In terms of durable Marvel characters, the Blob is one of the toughest there is. His primary mutation helps him absorb all sorts of damage; from explosions to energy blasts, the Blob can no sell some pretty hard hits. That's actually the problem with his secondary mutation - Fred's stretching powers compromise his durability and leave him vulnerable. The first time he stretched, the dude turned into a puddle.

7 7. Stronger: Black Tom Cassidy's Plant Form

"Black" Thomas Cassidy is a mutant with a very complex past. He's the cousin of Sean Cassidy - best known as the X-Men Banshee. Tom and Sean developed feelings for the same woman way back when. The cousins were both so in love with Maeve Rourke, they turned against each other. Sean eventually won Maeve over, but Tom secretly adopted his cousin's daughter and raised her.

RELATED: Post-"Apocalypse," 7 X-Men Villains Ready for Prime Time

All of these events made Tom hate Sean. When Thomas developed his first powers, he used them to become a criminal. Tom later gained new powers that gave him control over plants, superhuman strength, and the ability to become a giant!

6 6. Weaker: Kid Omega's Non-Corporeal Form

Kid Omega Quentin Quire

True to his name, Kid Omega is a powerful mutant psychic and telepath. To be more accurate, the Kid is an Omega level mutant whose abilities are on par with Jean Grey and Emma Frost. Born Quintavius Quire, Kid Omega was naturally smart. But he only became smarter when he developed his primary mutant powers.

Now you might be wondering how an Omega level psychic could get any stronger. Well, we'll all have to keep guessing, as the Kid's secondary mutation had major drawbacks. Kid Omega couldn't use all of his primary powers, causing him to grow bored with his second mutation.

5 5. Stronger: Wolfsbane's New Tian Powers

Wolfsbane in X-Factor

Rahne Sinclair is a mutant who developed lupine powers at a very early age. Intolerance is a common problem that mutants have to face in the Marvel Universe. The thing is, most don't have to deal with that until they're adults. Rahne, on the other hand, faced persecution and bigotry when she was a child.

Dubbed "the wolf girl," Rahne lived on the fringes of society for most of her life. She eventually found her way to Xavier's school much later in life. She learned how to control her primary powers there and found the home she never had. Later on, Wolfsbane developed a host of new abilities; she could greatly extend the length of her claws as well as split herself a pack of wolves!

4 4. Weaker: The Stepford Cuckoos' Flight

Stepford Cuckoos Phoenix

The Stepford Cuckoos are a group of identical twins that each have psychic powers. These sisters are the result of the Weapon Plus program and their morally unethical experimentation. The Stepford Cuckoos are telepathically linked to each other via a hive mind. Their combined mental might is great that they can also house the Phoenix Force.

RELATED: X-Men Black: Emma Frost Pulls Off the Ultimate Power Move

Here's the thing about the Cuckoos; their secondary mutation gave them the ability to fly. Now flight is a phenomenal power in and of itself. It just pales in comparison to the Cuckoos' other powers. It's also worth noting that the Cuckoos were 'born' with Emma Frost's diamond skin ability.

3 3. Stronger: Toad's Flaming Tongue

Ray Park as Toad In X-men

Toad is another well-known mutant that even casual comic book fans will likely recognize. Born Mortimer Toynbee, Toad had a rough upbringing, to say the least. His parents abandoned him at such an early age that he has no clue who they are. Mortimer's abilities manifested at an early age, making him the target of much ridicule and hate as a child.

When he got older, Toad joined Magneto's Brotherhood of Mutants. There, Mortimer found a family that accepted him for who he was. He also learned how to control his primary abilities with greater ease. Later on, Toad developed a secondary mutation set his tongue ablaze without harming him!

2 2. Weaker: Husk's Personality Swings

Husk (Paige) ripping off her skin in Marvel Comics panel

Mutant abilities are so interesting because they're so varied. Some mutants have simple abilities like increased strength or heightened durability. Others have more benign gifts like teleportation or inter-dimensional travel. Paige Guthrie, also known as Husk, is one such mutant with a very unique power.

She can shed her normal, mostly carbon-based skin in exchange for new powers. Paige's powers are very versatile, allowing her to adapt to almost any scenario. However, Her secondary mutation actually counters her primary powers. At one point in time, Paige would also swap personalities when she'd shed her skin. Moreover, she'd experiences blackouts and briefly lose her memory.

1 1. Stronger: Elixir's Super-Powered Dark Side

Elixir heals everyone

We've talked about Omega level telepaths a few times in this list. Elixir is the first and only Omega level healer to grace this article. This guy's powers are out of this world; he can help others heal from drastic wounds, recover lost limbs, and beat life-threatening illnesses! Joshua Foley's primary mutant powers have saved countless lives. Perhaps that's why his secondary mutation is so frightening.

After healing himself, Joshua gained the ability to kill others instantly. To make matters worse, Joshua would transform into a terrifying form with pitch black skin. Elixir gained the ability to take life as well as give it.

NEXT: 10 Times Storm Proved She Was The Most Powerful X-Man Of All-Time