Thats where Privileged Position comes in as a hexproof enabler
Engulf the Shore is also great in mono-blue decks, and dont sleep on some of the creature-based ones like Scourge of Fleets
Darkness and Metal types, Baby Pokmon, and Pokmon Tools all got their start here
Normally, players would get a chance to respond before the ability resolves, but Doubling Cube's ability is a mana ability, so 605.3b says An activated mana ability doesnt go on the stack, so it cant be targeted, countered, or otherwise responded to
Graded Population Report: Great Ball [Reverse Holo] #92 Visualize the distrbution of grades in the chart
Eerie Ultimatum is awesome in highlander formats like EDH, while Emergent Ultimatum saw a lot of Constructed play in ramp decks