Shadowverse

Unfortunately (or perhaps fortunately?), the main problem with the Worm isn't the lack of AoE spells, but rather the banish/transformation effect, the need to play it perfectly, the useless vanilla body that slows down your tempo, the lack of good tools for board control, the lack of good followers, the lack of pressure, and the need to play all parts of the combo (Viridia and its evolution, Ram, Claw, Chain, Gift to the Bloodseekers) at exactly the right time, and all while not dying, which is difficult when you lose half your health just by playing cards, without any effort from the opponent. It's more accurate to consider this deck as a Darkfist deck that is played with or without the Worm; the very concept of a "Yhorm" deck has completely died, not even having time to live, and all these points are also relevant for DFBs. So... having one more reliable AoE spell is certainly good, but it consumes Viridia's evolution and won't solve the deck's real problems.
However, the Behemoth will be excellent in the Mice deck, and possibly even in a "Yhorm" deck, taking the slot of... drumroll... Yhorm himself, lol. Indeed, why play a useless vanilla 5-5 body that will be banished and won't even be able to trade, unless it absorbs its evolution, if you already have a new, reliable AoE for the same evolution cost, and if you can play an overstatted body with Demonic Strike, which can also damage the opponent's face, bringing them closer to the DFB turn, and clear an enemy follower.