Drain Power is interesting, because while it is a sorcery that costs UU rather than an instant that costs 2U, it puts your opponents mana into your pool
If youre able to spend ten or more mana on Finale of Devastation, you get to give all your creatures +X/+X and haste for the turn
Whether or not Zur should see play ultimately depends on the strategy and synergy of the deck it is being considered for
Green is also exceptional at creating an immense mana advantage, typically with cheap cards like mana dorks (Llanowar Elves, Badgermole Cub) and land-based ramp, which is pretty unique to green (Rampant Growth, Cultivate)
For MTG collectors, an Alpha Black Lotus isnt just a trading cardits the holy grail, the dream acquisition, and the ultimate status symbol