Whispering of the Wilds and Map the Wastes are the main ramp cards and surprisingly, they are both very strong
Sage of Ancient Lore immediately becomes a 10/10 or bigger - great if you can give it haste
At the same time, it's walking on the thin line between "broken" and "win more," and we all know how bad "win more" cards truly are
The permanent card you reanimate from Winters Delirium trigger isn't an incredible payoff either, especially given you have to exile other potential set-piece cards to get the most out of it
While it technically gives your opponent extra colorless mana, would you rather your opponent had an extra land or a Gideon, Ally of Zendikar
Build up your Energy counters quickly over two turns while delaying your opponent, before spending the Energy to play a powerful card for free