Originally Posted by
Wankyudo
That progression wall will be Ishida Masazumi's (The first event) event if your luck is horrible (Which if you find yourself struggling for 5*, it is)
100 Stages and 90-100 is downright impossible without several fully stats/godified/remodeled 6* units of multiple typings, and while you can get her to drop her rate is exceedingly low prior to those ones. Hell her drop rate is low in those ones too, wasn't until Toshimasa Maeda where drop rates got better.
Though you may luck into getting all the copies needed to make a 6* Masazumi, in which the next wall will be the first ultra-hell dungeon (Also fondly known as bullshit snek). Full water team of 6* with immunity to fire + Nene is required to pass it; there's just no getting around that one.
Unless they nerf them, but they are probably not going to do that because they're going to want everybody to shell out the dough for the 5* paid gachas.