Cyclonic Rift gives the other player an opportunity to replay the permanent with protection, but usually, there are so many things one tries to play after that it might not be a priority
If the targeted creature becomes an illegal target before Drag Under resolves, you wont draw a card
Self-protection, plus very strong creature protection from noncombat damage protection make this wall great alongside pingers and any of the best activated abilities your deck runs
Once you have your Phyrexian god, the gameplans simple: Cast some effects that force your opponents to draw cards on their turns and follow it up with discounted X-spells
The Most Valuable Edge of Eternities Cards Right Now That includes one card, Sothera, the Supervoid (Singularity Foil) , that's already going for over $2000 on resale sites like TCGPlayer and eBay
Any abilities that are gained by the permanent are ignored, including abilities gained due to a resolving spell or ability or copy effects