The card of the week is Hibernation’s End a tutor that has Cumulative upkeep.
Cumulative Upkeep is seen as a bad mechanic, and is often enough to stop a card from seeing play. Thanks to Mystic Remora Cumulative upkeep is at least a well understood mechanic unlike Rampage, Soulshift or Cipher. The reason Cumulative Upkeep is seen as a negative is that in addition to the initial Mana Value (MV) there is an increasing tax you have to pay each turn to keep the card around. You can read more about how Cumulative upkeep works here.
Hibernation’s End is an Enchantment for 4G that has cumulative upkeep of 1. Whenever you pay the upkeep you can search your library for a creature card whose MV is equal to the upkeep cost and put that creature into play. This means that the turn after you cast it you can tutor for a 1 MV creature to play, the following turn a 2 MV creature. This allows you to tutor for the best creature in your deck whose MV is equal to the upkeep cost. Unlike other cards with Cumulative upkeep this means that the upkeep cost is not “wasted” but directly contributes to your board state.
However, an MV of 5 is quite steep and means that you will not be able to consistently get it out early. In addition it will need to survive a full turn rotation before it starts to become effective. It can also be restrictive as the creature’s MV must equal the upkeep cost paid.
It synergies really well with Braids of Fire, another card with Cumulative upkeep.
Hibernation’s End is a flexible card that works best in creature heavy decks. It is as it most powerful in toolbox decks that tutor specific creatures for specific situations. For example in a Yarok, the Desecrated enter the battlefield (ETB) deck. As well as being useful in elf tribal decks such as Lathril, Blade of the Elves; Ezuri, Renegade Leader or Marwyn, the Nurturer.