Earth Knuckles. This basic arcana is not only superior to Stone Shot in terms of damage and knockback, but it also looks cooler. It basically pummels your enemies with earthen fists.
Spike Track. One of the better dash arcana, it leaves behind a trail of spikes that deal with the rest of the enemies. While you dash forward, you also deal 30 points of damage, which is quite significant for a dash attack.
Earthquake Axe. There are some really powerful standard earth arcana, such as Seismic Entry, but their cooldown times make them unusable. Earthquake Axe, on the other hand, has only 4 seconds of cooldown, 30 damage, and 15 knockback.
Terra Ring. All signature earth arcana are quite impressive, but Terra Ring has the best animation as it pulverizes the ground beneath the foes. It also strikes with multitudes of spikes that each deal up to 15 damage.