No standalone cards without archetype affiliation don't need prefixes, and many powerful classic cards have none (Raigeki, Mirror Force, Dark Hole)
These include A Game of thrones, Arkham Horror, Battlestar Galactica, Chaos In The Old World, Cosmic Encounters, Descent, Doom Board Game, Galaxy Trucker, Game of Thrones CCG, Gears of War, Mansions of Madness, Mission: Red Planet, Runebound, Space Hulk, Star Wars: Imperial Assault, Starcraft The Board Game, Tide of Iron, Times Up and World of Warcraft: The Board Game
manga and anime series, play as a duellist, commanding monsters, spells and traps in an exciting trading card game, complete with beautifully drawn cut scenes and animations
Translation: Yugipedia What do you think
SDY-021 - Monster Reborn
Key searchers for the Egyptian Gods include "Soul Energy MAX!!!" (if it is in the GY, which can be done with "Foolish Burial Goods") for Obelisk, "Thunderspeed Summon" for Slifer and Ra (requires setup of Three Musketeers of Face Cards), and "Ancient Chant" + "The True Sun God" for Ra