Hiden temple of necrovalley prevents special summoning except gravekeeper monsters only and also gravekeeper archtype are the only cards not affected by necrovalley if necrovalley is on the field if i am not wrong
I have just walter to write this comment amd now I am proud of what I wrote.. Bestiari kicks necrovalley out as I expected.. moreover the big beast gyzarus is ön the way nobody can compete with glads
The overpowered meta can be thought of as a pay to meet a Gyzarus release in a main box. However, I doubt it ll occur in a close time, maybe during xyz era