Featuring a fan-favorite character is one way to propel a card through the charts, as indicated by the expensive Enchanted Elsa card from The First Chapter
Apart from the one I have, I know of two more
Fertilid is a particularly good fit for Marath, as he can put counters on other creatures
Finally, Murmuring Mystic is incredible
But you should also keep an eye out for control elements , like Sword Coast Serpent, Sapphire Dragon, Oceanus Dragon, and Juvenile Mist Dragon to keep your opponents on lockdown until youve built up the resources needed to close out the game
Benthic Biomancer Another merfolk all-star, Benthic Biomancer goes in more decks, including counter shenanigan decks like Chisei, Heart of Oceans or Goldberry, River-Daughter