How MTG's Terra Commander Decks Work Much like Kefka, Terra, Magical Adept's main strategy is to self-mill cards from the deck to fill the graveyard

Instructor: Favorite Card: Evilswarm Ophion Deck: Evilswarm Deck 3 Evilswarm Heliotrope 3 Evilswarm Castor 3 Evilswarm Kerykeion 1 Evilswarm Thunderbird 3 Evilswarm Mandragora 2 Maxx C 3 Ash Blossom & Joyous Spring 2 Ghost Ogre & Snow Rabbit 3 Rescue Rabbit 2 Dark Armed Dragon 1 Effect Veiler 2 Called by the Grave 2 Unexpected Dai 1 Infestation Pandemic 1 Reinforcement of the Army 1 Harpies Feather Duster 1 Raigeki 1 Infestation Infection 1 Compulsory Evacuation Device 2 Infinite Impermanence 2 Solemn Strike 1 Number 39: Utopia 1 Number C39: Utopia Ray 1 Number S39: Utopia the Lightning 1 Number 41: Bagooska the Terribly Tired Tapr 1 Evilswarm Exciton Knife 1 Abyss Dweller 1 Tornado Dragon 1 Zoodiac Chakanine 1 Zoodiac Drident 1 Light Dragon @Ignister 1 Evilswarm Nightmare 1 Evilswarm Bahamut 1 Evilswarm Ophion 1 Steelswarm Origin 1 Borreload Dragon Deck Concept Special Summon the Normal Monsters Evilswarm Heliotrope from the Dec with the effect of Rescue Rabbit, and then fight by using them as materials to Special Summon Xyz Monsters

That means each song is included four times, maximizing odds you can reliably find them each game
Its ability to special summon itself by discarding two water monsters was seen as worth it to get a 2400 attack monster, and the discard is naturally mitigated by how the deck works
The amusing one here is Herald of the Host, which I presume hopped over the bulk line due to Giada, Font of Hope
According to WotCs article on the creature type update, there was a debate about issuing an errata on creature types because it would create a lot of confusion concerning old cards