40 cards where the card types include “creature” and the color identity ≤ GRU and (the card is available on Paper) and the mana value = 9

Apex Altisaur (The Lost Caverns of Ixalan Commander #232)
Arboretum Elemental (Guilds of Ravnica #122)
Artisan of Kozilek (Commander Masters #801)
Blast-Furnace Hellkite (The Brothers' War Commander #12)
Body of Jukai (Betrayers of Kamigawa #121)
Breaching Leviathan (Commander 2014 #12)
Cavern-Hoard Dragon (Tales of Middle-earth Commander #31)
Chiss-Goria, Forge Tyrant (Phyrexia: All Will Be One Commander #25)
Chromescale Drake (Darksteel #20)
Colossus of Sardia (Tenth Edition #317)
Crimson Hellkite (Seventh Edition #178)
Depth Charge Colossus (The Brothers' War #78)
Drownyard Behemoth (Eldritch Moon #4)
Fire Dragon (Portal #125)
Furnace Dragon (Darksteel #62)
Grozoth (Ravnica: City of Guilds #53)
Hand of Emrakul (Rise of the Eldrazi #5)
Herigast, Erupting Nullkite (Modern Horizons 3 #8)
Hulking Metamorph (The Brothers' War #79)
Inkwell Leviathan (Double Masters #55)
Kozilek, the Broken Reality (Modern Horizons 3 #10)
Krosan Colossus (Murders at Karlov Manor Commander #176)
Lava-Field Overlord (Battlebond #60)
Leviathan (Time Spiral Timeshifted #23)
Mockery of Nature (Eldritch Moon #10)
Myojin of Life's Web (Champions of Kamigawa #229)
Nullstone Gargoyle (Ravnica: City of Guilds #266)
Phyrexian Triniform (Commander Masters #969)
Sailors' Bane (Commander Legends: Battle for Baldur's Gate #93)
Skitterbeam Battalion (The Brothers' War #165)
Sproutback Trudge (Commander 2021 #68)
Suncrusher (Fifth Dawn #159)
Teeka's Dragon (Mirage #320)
The Tarrasque (Adventures in the Forgotten Realms #207)
The Unspeakable (Duel Decks: Mind vs. Might #13)
Thing from the Deep (Portal #73)
Titanoth Rex (Ikoria: Lair of Behemoths #174)
Triplicate Titan (Commander 2021 #79)
Void Winnower (Battle for Zendikar #17)
Zodiac Dragon (Portal Three Kingdoms #131)

The message was clear to Sorin—time to search for something else.