The damaged creature will be exiled if it would die for any reason that turn, not just if it dies due to damage from Incendiary Flow

Aesi, Tyrant of Gyre Strait Aethersquall Ancient Archipelagore Arixmethes, Slumbering Isle Awoken Horror Benthic Anomaly Benthic Behemoth Biblioplex Kraken Biolume Egg Biolume Serpent Bladecoil Serpent Bog Serpent Breaching Leviathan Brinelin, the Moon Kraken Caetus, Sea Tyrant of Segovia Charix, the Raging Isle Cryptic Serpent Deep-Sea Kraken Deep-Sea Serpent Deep-Sea Terror Denizen of the Deep Dirgur Nemesis Dreamwinder Eater of Days Famished Worldsire Floodtide Serpent Frilled Sea Serpent Gearseeker Serpent Glacier Godmaw Grappling Kraken Grozoth Gyruda, Doom of Depths Gyruda, Doom of Depths Harbor Serpent Hullbreaker Horror Icebreaker Kraken Iceridge Serpent Inkwell Leviathan Isleback Spawn Jokulmorder Junk Winder Kederekt Leviathan Kiora's Dambreaker Koma, Cosmos Serpent Koma, Cosmos Serpent Koma, World-Eater Kraken Hatchling Kraken of the Straits Krothuss, Lord of the Deep Kukemssa Serpent Lava Serpent Leviathan Lightning Serpent Loch Mare Lochmere Serpent Marjhan Monstrosity of the Lake Nadir Kraken Nemesis of Reason Nimbus Swimmer Pearl Lake Ancient Polar Kraken Reservoir Kraken River Serpent Ronom Serpent Rot-Tide Gargantua Sandbar Serpent Scourge of Fleets Scrapdiver Serpent Sea Monster Sea Serpent Segovian Leviathan

You can find them in all booster types
However, if you think about it, Pokemons spent a ton of time and resources on developing this game