46 cards where the mana value = 3 and the power = 5

A-Acererak the Archlich (Adventures in the Forgotten Realms #A-87)
Acererak the Archlich (Adventures in the Forgotten Realms #87)
Ammit Eternal (Hour of Devastation #57)
Arc Runner (Magic 2011 #123)
Athreos, God of Passage (Journey into Nyx #146)
Avatar of Discord (Archenemy #79)
Blistering Barrier (Mirage #159)
Civilized Scholar // Homicidal Brute (Innistrad #47)
Civilized Scholar // Homicidal Brute (Innistrad #47)
Conduit of Storms // Conduit of Emrakul (Eldritch Moon #124)
Conduit of Storms // Conduit of Emrakul (Eldritch Moon #124)
Cultivator's Caravan (March of the Machine Commander #354)
Cunning Bandit // Azamuki, Treachery Incarnate (Betrayers of Kamigawa #99)
Dormant Gomazoa (Rise of the Eldrazi #62)
Drinker of Sorrow (Legions #66)
Foreboding Statue // Forsaken Thresher (Innistrad: Crimson Vow #256)
Foreboding Statue // Forsaken Thresher (Innistrad: Crimson Vow #256)
Gadrak, the Crown-Scourge (Core Set 2021 #146)
Gilded Assault Cart (Kaldheim #390)
Great Desert Hellion (Alchemy: The Brothers' War #19)
Hanweir Watchkeep // Bane of Hanweir (Innistrad #145)
Hanweir Watchkeep // Bane of Hanweir (Innistrad #145)
Heliod, Sun-Crowned (Commander Masters #29)
Honeymoon Hearse (Innistrad: Crimson Vow #160)
Kaslem's Stonetree // Kaslem's Strider (The Lost Caverns of Ixalan #197)
Kaslem's Stonetree // Kaslem's Strider (The Lost Caverns of Ixalan #197)
Kefnet the Mindful (Amonkhet #59)
Lavacore Elemental (Planar Chaos #103)
Lovestruck Beast // Heart's Desire (Commander Legends: Battle for Baldur's Gate #827)
Mardu Outrider (Arena Beginner Set #52)
Master of the Feast (Journey into Nyx #75)
Nulltread Gargantuan (Alara Reborn #102)
Phantasmal Abomination (Rise of the Eldrazi #80)
Pharika, God of Affliction (Journey into Nyx #154)
Phylactery Lich (Core Set 2019 #113)
Phyrexian Negator (Duel Decks: Phyrexia vs. the Coalition #1)
Pitiless Horde (Dragons of Tarkir #112)
Plague Belcher (Amonkhet #104)
Qal Sisma Behemoth (Dragons of Tarkir #149)
Rage Nimbus (Rise of the Eldrazi #160)
Rhonas the Indomitable (Amonkhet #182)
Ruinous Minotaur (Zendikar #145)
Screeching Bat // Stalking Vampire (Innistrad #114)
Screeching Bat // Stalking Vampire (Innistrad #114)
Skaab Ruinator (Innistrad #77)
Spined Fluke (Urza's Saga #160)
Steel Leaf Champion (Dominaria #182)
Stoic Ephemera (Dissension #19)
Thassa, God of the Sea (The Lost Caverns of Ixalan Commander #176)
Wayward Swordtooth (The Lost Caverns of Ixalan Commander #263)
Woolly Thoctar (Modern Masters 2017 #203)
Xantcha, Sleeper Agent (Commander Masters #362)

Though this query has ended, its relics still slumber in New Argive.