For that part OK, but people say that they are back row heavy and that they always end up destroying yours before doing a synchro. If that happens all the time wouldn't this trap become useless?
Although the effect works on Shiranui it is not good.
They destroy a backrow each time they banish a monster. In the end you will turn their monster to zero attack during the main phase only. Then they simply synchro with the zero atk monster and it's like you constantly keep wasting your valuable resources.
Because Shiranui is expensive. If this F2P card really allowed you to get easy victories against a money grabber deck then Konami would have banned this card instead.
In Duel Links MORE money wins against LESS money. Your duels aren't determined by skill.
The good advice you mentioned, could it be about:
no one is currently using this trap against Shiranui because they are going to force you to activate it before the battle phase and then Synchro with their 0 atk monster anyway? Effectively making this trap useless?
Because this is currently the ONLY card that I could think of to not lose against Shiranui.
Its probably becuase squiresaga. Shiranui usually clear your backrow before even start attacking. I believe you will at least make squiresaga has 0 atk, but your opponent probably has 2-3 backrow ready and spectralsword in GY. He will just spam squiresaga each turn until you run out of backrow, while maintaining combo from banished shiranui. In the end, the effect is work, but not that effective.
LoL.
I'm kinda sure that if this trap cards instead had the effect:
put all Red-Eyes/Blue-Eyes to 0 atk; those guys would have had to at least respect you. Meta or not.
Shiranui on the other hand just say:
You put me to zero? I will ignore you anyway.
Konami made Shiranui broken on purpose so as to motivate people to buy it. Especially those who have already spent all their gems on their main archetype like Lightsworn BE, Dark Lord, etc.
If you want to win then buy Shiranui even if you have no gems.
If you find losing fun then you may save your gems.