Many of the mythic tier rating sound very harsh. The competition they’re up against is very fierce. I’ve split them across the tiers as a bell curve as best I can.
In DonT’s case it is Duel that makes all the monsters in his FL perform far better than expected. The general rule of the tier list is lower tier monsters are as good as S+ monsters under the right circumstances… which is what we see in DonT’s team.
For reference on mythics… an F tier mythic is probably equivalent to an A tier legendary. Hence, D-E mythic = S-, B-C = S, S- -A = S+ and S+ -S are in a league above. I’ll actually add that to the tier list explanation section. Basically, the general quality of mythics is much higher but they’re packed more tightly in power level I think.
EDIT: I added this information in a clearer post here: 🏆 Neo Monsters tier list (see first post) 🏆 - #313 by Killerdog