Bloon Melter is an Advanced Powercard in Bloons Card Storm, introduced in version 2.0. It destroys a target Bloon on the player's side and does 20 damage to the opponent. It will trigger any On Popped or On Destroyed effects on the target.
The main purpose of Bloon Melter is to destroy friendly bloon(s) in favor of the player. The face damage is low, but can add up over time.
The player can use Bloon Melter to deactivate an opponent's Corvus Academy of Arts without using a Monkey removal.
If you are going to use it to damage the hero however, use it on bloons that are weak from the start or too weak to fight the opponent such as Swarm Red Bloon.
Bloon Melter can synergize with Bloons with an "on destroyed" or "on popped" keyword such as The Eternal, Volatile Bloon, or Sentinel Bloon. The Eternal or Volatile Bloon have effects that can justify Bloon Melter in a deck, and the former is usually the main incentive for this card.
Eternal decks may rely on Bloon Melter to keep building its HP and re-playing the stronger Eternal, plus more Bloontonium. Post nerf, The Eternal’s slow scaling on pop may make the strategy unreliable.
Black Bloons give a card right away upon popping, which may be helpful if desperate for more card draws.
Using this with Sentinel Bloon gives you the effect of a Bloon Strike for 2 gold and 5 Bloontonium, and using it on two gives you a MOAB Strike for 4 gold and 10 Bloontonium. This makes melter a decently good choice for Mountain Obyn Burn decks.
Bloon Melter can also be used for removing bloons for Hastening Bloon consistency, although doing so is expensive and generally unadvised.