For example, even if we interpreted your library as part of the battlefield for this purpose, slipping one into the card sleeve of a card in your library during a search effectively marks your deck, and that's not allowed
is a game with a lot of history, and one of the most prevalent decks in its history is Monarchs
Pendrell Mists - The Tabernacle at Pendrell Vale in enchantment form
And while it doesnt protect itself quite as completely as Nezahal, Primal Tide, its nice to know you can save your commander from all non-exile removal

Commander 1Ganax, Astral Hunter 1Feywild Visitor Planeswalker 1Sarkhan, Fireblood Creature 1Minion of the Mighty 1Magda, Brazen Outlaw 1Magda, the Hoardmaster 1Sprite Dragon 1Dragonspeaker Shaman 1Glin, Dwarf Emissary 1Swashbuckler Extraordinaire 1Firkraag, Cunning Instigator 1Renari, Merchant of Marvels 1Territorial Hellkite 1Vengeful Ancestor 1Lozhan, Dragons' Legacy 1Scourge of Valkas 1Wrathful Red Dragon 1Incinerator of the Guilty 1Lathliss, Dragon Queen 1Scourge of the Throne 1Shimmer Dragon 1Steel Hellkite 1Dragon Mage 1Drakuseth, Maw of Flames 1Furnace Hellkite 1Knollspine Dragon 1Skyline Despot 1Terror of Mount Velus 1Thunder Dragon 1Tyrant's Familiar 1Blast-Furnace Hellkite Sorcery 1Winged Words 1Distant Melody 1Anzrag's Rampage 1Echo Storm 1Volcanic Torrent 1Blasphemous Act 1Dragonstorm Instant 1Arcane Denial 1Lofty Denial 1Magmaquake 1Negate 1Silumgar's Scorn 1Chaos Warp 1Draconic Lore Artifact 1Sol Ring 1Arcane Signet 1Izzet Signet 1Carnelian Orb of Dragonkind 1Cursed Mirror 1Inspiring Statuary 1Lapis Orb of Dragonkind 1Worn Powerstone 1Bident of Thassa Enchantment 1Reconnaissance Mission 1Rain of Riches Land 1Command Tower 1Demolition Field 1Ferrous Lake 1Fiery Islet 1Frostboil Snarl 9Island 1Izzet Boilerworks 15Mountain 1Myriad Landscape 1Path of Ancestry 1Secluded Courtyard 1Shivan Reef 1Spinerock Knoll 1Sulfur Falls 1Temple of Epiphany 1Temple of the Dragon Queen This list is a great start to Izzet Dragons and should be fine in both Bracket 2 and 3
