Low tiers doesn’t mean they can’t be used to get top 10. In the right setup you can make a lot of monsters perform very well. A tier also isn’t low at all… just look at how stacked that tier is with mythics you commonly see in top teams and they perform well.
It’s a complex monster, like a lot that have come out this year. There’s a few dimensions to it that aren’t immediately obvious like how you can put teammates to +0 entrance speed and hellish shriek is infinite use so you can chain the first shriek into more if you put all your teammates behind the enemies. My initial reaction was “This looks too unreliable but I’m sure someone will break it” and then when I realised it’s easier to do than I thought it dawned on me just how broken it might be.
The best combo I can think to do with it right now is: Mortilys, Bastia, Kuromasa, Gabrielle.
What you do is sweep all four enemies and your monsters are high enough TU to be behind all the enemies that you can hellish shriek to push them back enough to do the same again and Bastia blocks all potentially annoying entrances. You can also adjust move TU to make them similar enough that they all get a turn pretty much together, rather than one or two being behind enemies (increase TU on Gabrielle and Bastia so it’s 160TU for both and 170TU on Kuromasa).
If you can pull that off twice reliably that’s half a team gone, you’ve probably got the win guaranteed, but you could potentially chain it further.
So I have a feeling people will use it like this and the monster will need to get nerfed like making hellish shriek single-use.