What would certain Champions Fear?
Here's a list of what I believe certain champions would see when they get feared or affected by Malzahar's Malefic Visions. For many champions, I noticed that many of them would have suffered from PTSD, so in my head canon, these champions would remember their past traumatic memories if they get feared or Space Aids.
Ahri: Having her life essence painfully drained out by her past self.
Amumu: Being completely alone.
Anivia: Transforming into a merciless Blackfrost Cryophoenix.
Azir: Witnesses his family and his Shurima be destroyed by the power of his failed Ascension.
Blitzcrank: Loss of his sentience.
Brand: Entombed in ice again (claustrophobia and frigophobia)
Draven: No one cares who he is, or ironically, Draven is intensely creeped out by seeing everyone and everything having his face.
Galio: Being completely petrified and helpless as his allies die around him, in a situation which resembled how his creator died.
Graves: Being locked away into a tiny cell.
Jinx: Her guns decided to turn against her; they malfunction and blow up in her face.
Kassadin: He sees the Void's monsters consume Runeterra.
Kog'Maw: Becomes so immensely hungry that he eats himself.
Lee Sin: Sees the boy he killed and village he destroyed when he was a summoner in training.
Lissandra: Relives the experience of her eyes being gouged out by an Ursine during her youth.
Lucian: Becomes what he hates, a cruel apparition, not unlike Thresh.
Lux: Has a mental breakdown.
Master Yi: His traumatic memories of his village being devastated by Singed's chemicals re-emerge.
Nami: Her people are completely wiped out, extinct. She failed in her quest to find the moonstone.
Nidalee: Her cougar family is slaughtered and her home in the jungle is razed to the ground.
Olaf: He peacefully passes away instead of dying in combat.
Riven: Goes through the PTSD incident where she and her comrades were gassed by Singed.
Shaco: Death becomes boring, no longer funny or entertaining for him.
Sejuani: She and her tribe subjugated or she sees herself becoming a soft, delicate housewife.
Sion: Briefly gains clarity of what he has become and becomes mortified of his undead condition.
Sona: Loses her ethwahl, her most invaluable tool which allows her to communicate.
Soraka: Being torn apart by Warwick.
Syndra: Loses her magic and her floating fortress crumbles on top of her.
Twisted Fate: Being unable to control his teleportation ability. Lady luck has essentially left him.
Vayne: Being killed by the witch who killed her parents.
Varus: The Pit of Pallas swiftly corrupts his body. His will is now Pallas'.
Vel'Koz: Being dissected alive.
Viktor: His logical, Evolution driven mind is overwhelmed by the depressive thoughts which he experienced when Blitzcrank was stolen from him. His body is reverted to fully human.
Yasuo: Haunted by the ghost of his brother, Yone, who he had killed.
Alcohol prohibition laws.
Dying without anyone remembering who he is.
You will remember Yorick Mori
Being hung by his own chains once more.
Willump / Nunu dying alone without Nunu / Willump
: Witnesses Zed slaughtering Shen and Kennen, because she didn't act quicker to kill Zed like she planned / Being told by her mother that she failed being the successor of the title Fist of Shadow.
: Avarosa tribe being slaughtered and she is kept as a prisoner/trophy just to witness Freljord collapse further due to winter/further conflicts.
: A horde of demons trampling over him, but enough so he did not die, but wakes up just in time to see everything he tried to protect destroyed.
: The destruction of Piltover. And apparently she's to blame because she wasn't quick enough to solve one crime.
: Seeing the corrupt nobles he executed came back to life and reclaims position within Noxus, once again running it down to ground. They also get immunities against Darius' head chop.
: Reliving what happens if the Moon didn't save her from the execution by the Solari.
: Seeing the House Laurent name further down the mud.
: Saw someone else usurp his claim as the most dreadful pirate in Valoran and continually beating him until he got no crews left.
: Seeing Demacia fall and everyone believing that Demacia's values are nothing but fraud (this is especially possible with Lux's League Judgment. If everyone ends up believing that because of it, Demacia's creed of protection of justice are considered fraud, this won't do well for Garen)
: Getting too blood thirsty that his fellow Demacians assassinate him before he became a big threat.
: Zed is forgiven and the Kinkou Order rose again... but this was all Zed's trick to let everyone else's guard down, because of Kennen's suggestion, the Order fell to an even worse crisis, because Shen and Akali are the first casualties.
: Her illusion gains sentience, and then kills her to take over her place. Or worse, her illusion dumps her to a mirror so she can take over LeBlanc's place as the original just watched. (Anyone reading Doraemon manga should know this...)
: Being declared heretic by the Solari and executed.
: Veigar and Gnar and even Pix left her alone, thinking that she's annoying, and then Lulu becomes a psychotic Yordle much like Veigar.
: Meets the pirate that killed of her mother... then finding out that she's beaten so soundly, and she is imprisoned, which has an effect of the plummet of her reputation as a bounty hunter and her charisma amongst the people of BIlgewater.
: The souls he enslaved turn against him and overpower him.
: Defeated by Renekton, he's sealed inside a pyramid by Renekton to 'feel his pain'. Centuries later, Nasus was released and became as crazy as Renekton all while the cycle of life and death are in chaos with no one to deal with it.
: The Rakkor tribe is destroyed via a strategy, rather than a fair war/combat.
: Being imprisoned. By Nasus. AGAIN.
: Slips up and struck down Zed with anger in his father's name when he's supposed to surpress them, causing him to lose the Eye of Twilight and proven unworthy to protect balance.
: Seeing Jarvan flat out say she's worthless, has no place in Demacia and ditches her
: He becomes the psychotic killer that he feared himself to the point of befriending Tristana.
: Becomes the first victim of 'psycho Teemo'
: Even with his anger further, Aatrox still beats and eventually killed him.
: Loses her fight against Jinx and witnesses her blowing Piltover up.
: Sees Jarvan dead, showing that he failed to protect the Lightshield family.
: Losing to Morgana, OR the crushing guilt she'd feel over Morgana's death if she wins.
: Losing to Kayle, OR the thought that Kayle was right all along and, after they destroy the angels, Morgana's adopted people will destroy themselves as well.
: Fears 
fears the day a surprise 
eats his bird.
Fire
: Losing his prophecy/connection to the void and being "human" again
: That the shadow overcomes him (Zed-Nocturne-Theory)/losing his ability and his Order of Shadow