If the user controls no card, this effect can be activated from the hand
You can remove counters from Steelbane Hydra to remove artifacts and enchantments, while Apocalypse Hydra trades its counters in to ping something
And it cant be overstated how useful it is that the naturalize effect comes from a channel ability, not casting a spell
send as many cards you control as possible to the GY, except from the Extra Monster Zone, and if you do, send cards your opponent controls to the GY, up to the number of your cards sent to the GY, then, inflict 300 damage to your opponent for each card sent to their GY by this card's effect
You can then cast Kellan, the Fae-Blooded from exile for just three mana, giving you a 2/2 with double strike and giving other creatures you control +1/+0 for each aura and equipment attached to Kellan