Storm isnt an evergreen mechanic, which means you wont see it in every single set like you do trample or haste
Forcing the opponent to discard an instant or sorcery removes an important damage spell, giving -2/-2 to a creature is likely to kill the majority of the creatures they field, and draining two life essentially undoes a spell's worth of damage
The deep teal used as the accent color makes you think of swirling, welcoming seas
Not to mention, you have the chance to get a nonbasic land with Planar Genesis, which could shift the game in your favor depending on what you hit
Master of Cruelties A niche card folks might not be aware of, Master of Cruelties does work in Rakdos decks that can easily ping you for the last life
Blue adds great tools like Reflections of Littjara to make extra rats as you cast them, and Homeward Path lets you steal back the donated rats for a fresh round of trouble