Is a very very important card this format.\
Especially against Hero beat when you are going second in games 2/3.
As hero Beat is considered to be one of the most represented decks in the OCG, you will have alot to fear clearing away their backrow.
For example, like me, when Im playing mermail Atlantean, people will side in 2 soul drain, or maybe skill drain, depending if they side any, which is likely.
Compared with the fact that they will set multiple backrows, or even 3 to 4 if there is starlight road/solemn judgment but i doubt many will use them in hero beat, at least not in the OCG.
Malevolent Catastrophe hurts the deck just as much as cards like Dimension Prison hurt the deck.
Having multiple Heavy Storm rocks and if they do use Solemn then its okay as i can use my saved up MSTs to hit the Soul Drain, and Marksman to hit the facedowns.
Hero beats best card vs Mermail is undoubtly super Polymerization because i cant chain to it, and it rids them of Megalo or any big beater easily. Also Absolute zero is incredibly hard to get rid of. Only D Prison, Mirror Force, and Dark Hole do it efficiently, and that, is to account that you will still lose resources in the process.
HOWEVER shining is mermails best friend as Megalo into discarding Armsman makes it miss timing.
From testing Mermails VS hero beat last week, its hard for heroes to match with mermail with the amount of s/t trap destruction you have. Chain Gemini Spark? Hit my Abyssphere, you chain your MST, k, you -1 yourself.