12 cards where the mana value = 9 and the power = 5

Blast-Furnace Hellkite (The Brothers' War Commander #12)
Blazing Archon (Ravnica Remastered #8)
Bringer of the Black Dawn (Fifth Dawn #43)
Bringer of the Blue Dawn (Fifth Dawn #26)
Bringer of the Green Dawn (Fifth Dawn #83)
Bringer of the Red Dawn (Fifth Dawn #62)
Bringer of the White Dawn (Fifth Dawn #7)
Chiss-Goria, Forge Tyrant (Phyrexia: All Will Be One Commander #25)
Drownyard Behemoth (Eldritch Moon #4)
Furnace Dragon (Darksteel #62)
Lava-Field Overlord (Battlebond #60)
Teeka's Dragon (Mirage #320)

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