It has a strong Jund theme of sacrificing triggers, sacrifice effects, and more
Ever since Alpha debuted with Lord of Atlantis and Merfolk of the Pearl Trident, Merfolk decks have existed
Tekuthal, Inquiry Dominus Tekuthal, Inquiry Dominus doubles your proliferate triggers, then protects itself by letting you pay Phyrexian blue mana and remove three counters from among your permanents to put an indestructible counter on it
The tribe does have certain strengths you can capitalize on and weaknesses you can mitigate, and you CAN make a sweet and effective deck that wins games
The only other obvious inclusions you could make are Monastery Swiftspear and perhaps Soul-Scar Mage
If there are specific cards or combinations of cards that your deck is built around, drawing more cards will help you find those key pieces faster