What I mean is, if you're a f2p, even with a wide box, chances are you won't always be able to 36 stars.
For the first time in my life I was able to get 36 stars. However what it took was premium teams and the abyss's buff dedicated to them.
For example, my Neuvilette usually hitting 35k a hit would never 36 stars, but thanks to the fact my dmg was buffed to around 50k, I got to finish these. As for my second team, I played Columbina, fischl, sucrose and flins, (averaging around the same damage as my c0r0 neuvilette team) and thanks to the perfect abyss buff, managed to get through it.
Basically, if the abyss don't want you to, you won't see the end of it, you might get great results consistently, the lack of margin to upgrade your build quickly becomes an insurmountable barrier forcing you to the only option left to become stronger... The credit card...
Is abyss really possible for f2p?