Water - Many dragons, especially Chinese ones, have power over water and weather
The Pokmon featured this year include: Charizard Dragapult Dragonite Drampa Eevee Hatenna Hydreigon Jigglypuff Koraidon Miraidon Pikachu Quagsire Rayquaza Roaring Moon Umbreon A few of the featured Pokmon are from the original series and games: Charizard, Dragonite, Eevee and Eevee's evolution, Umbreon from the second generation, Jigglypuff, and Pikachu, while others are from newer generations
Merfolk is a good one, Wizards can go mono blue (Patron Wizard), loads of combo decks and artifact ramp decks are also fine to be mono blue for
Having these creatures die and not having anything in the graveyard to reanimate hurts quite a bit, so in the early game, it is sometimes a good idea to try to discard a cheap creature like Evolved Sleeper or Faerie Vandal to Tainted Indulgence or Evangel of Synthesis so we'll have something in our graveyard to reanimate once our Puppeteers and Anointers start hitting the battlefield