Arden Angel will follow the same rules as our other mechanically unique Secret Lair cards and be globally available in boosters through The List in the future
The only way for your opponent to get around this is for them to draw a spell/trap card that allows them to destroy your field spell, like Mystical Space Typhoon
Aegar, the Freezing Flame Axelrod Gunnarson Bartel Runeaxe Beluna Grandsquall Bonny Pall, Clearcutter Bre of Clan Stoutarm Brion Stoutarm Dargo, the Shipwrecker Gorm the Great Jareth, Leonine Titan Kalemne, Disciple of Iroas Kroxa and Kunoros Kroxa, Titan of Death's Hunger Oloro, Ageless Ascetic Osgir, the Reconstructor Phlage, Titan of Fire's Fury Rosheen Meanderer Rosheen, Roaring Prophet Ruhan of the Fomori Storvald, Frost Giant Jarl Surtr, Fiery Jtun The Lady of the Mountain Thryx, the Sudden Storm Uro, Titan of Nature's Wrath Vogar, Necropolis Tyrant Yorvo, Lord of Garenbrig Zalto, Fire Giant Duke
You can even recall [P-209 Titamon] from your trash and repeat the cycle of deletion and revival to move your allies forward
(2016-04-08) A card with no mana cost, such as a land, has a mana value of 0