There are some fantastic AoE removal spells in the Modern format (e.g. Damnation). But the problem with these types of spells is that they remove all creatures. On the other hand, Ritual of Soot can become a very fine tool in the right deck that will leave your own creatures untouched.
Equip your deck with Phyrexian Obliterator, Kalitas, Gurmag Angler and Tasigur. When you need to remove dozens of token blockers from your opponent's side, then use Ritual of Soot and attack freely. That's what makes Ritual of Soot so special.
Another possibility is to play with green bests, such as Nullhide Ferox, Obstinate Baloth, Thragtusk, etc. In this case you can also rely on Assassin's Trophy as your additional removal.