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My guess is that Amulet of Safekeeping is R&Ds attempt to try and answer the question of how to ensure that Modern players can sideboard against multiple strategies at once so that your progression though a large Modern tournament is less matchup dependent
Derevi, Empyrial Tactician Rarity: Mythic Rare TYPE: Legendary Creature SUBTYPE: Bird Wizard CMC: 3 Mana cost: USD: $8.37 EUR: 9.13 TIX: 7.78 EDHREC RANK: 2844 (2/3) Flying When Derevi enters and whenever a creature you control deals combat damage to a player, you may tap or untap target permanent
The high life totals and inability to safely throw everything at one foe robs these spells of the flexibility that makes them good in the first place
Any continuous effects with a "for as long as" duration, such as that of Possession Engine (a card from the Aetherdrift release), ignore phased-out objects