Goldvein HydraGoldvein Hydra is a fantastic card, with some great keywords to act as an efficient attacker the turn it hits the board
You can even draw every single land from your deck and play them all if you have Abundance on the field when you play this, but it can be risky if one of your opponents is running mass land destruction
Since Containment Priest has flash, you can often catch people by surprise and put a stop to mass reanimation or even take most of the punch out of a huge Genesis Wave by preventing creatures from entering the battlefield
This may very well be the best Cube for Spell Queller ever built, and I expect decks that are heavy on countermagic and flash threats are great in this Cube
Couple that with a generation of players who had gotten older, nostalgic and gained access to disposable income, and very soon the act of owning Black Lotus became a status symbol in and of itself
A proxy can also be used in cases where a player owns a very valuable card, but does not wish to damage it by using it in actual play