That's very useful for two cards in particular: Beren and Luthien, which lets you make minions Strength -1 if there are Elf cards beneath your draw deck, and more importantly The Underdeeps of Moria
Hand Size: +1 Starting Life: -5 Starting Life: -5 Illustrated by David McDarby Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Not Legal Brawl Not Legal Legacy Not Legal Comp
Sultai can play the long game by having the best removal, card draw, recursion, counterspells, and late game threats
Black Market helps out here too, making more mana the more creatures die when it's on the battlefield
Its nice with the Restless cycle of lands that do something when they attack
Some cards listed may not be tournament legal in all formats so please check the banned/restricted list from Wizards of the Coast for the format you wish to play