Devoid is definitely parasitic, but so is every tribal deck and Infect. This is not a big deal. Here is an all-Devoid deck for the Battle Cruiser Cube.
Here are a couple of Kittens vs Tigers losses. The first one was against a powerful Abzan deck. The best I could do was pull off an exile out of Titan's Presence.
This deck is fun for kitchen table, and not so fun against powered up decks like the one I faced here. Still, if all I want to do is play these cards in real life at my kitchen table, its a fine deck.