Drill warriors effect to return to the field and return a card from the graveyard during the standby phase under Necrovalley does not work/happen. It should it Edison format.
Necrovalley’s text at this time specifies it only applies to targeted effects. Drill warriors effect does not target. This point is discussed a number of times in format Library Discord. (sorry can’t seem to link an example)
In addition, this point is noted (although not specifically mentioned for Drill Warrior) in Edisonformat.net.
The problem arises from all modern cards that interact with the GY in such a way that the modern errata of Necrovalley would negate the effect, all have a built-in check in their card scripts specifically looking for whether Necrovalley is active at the time.
As such, its not really feasible to change every such card script to try to accomodate such specifically for Edison.
Now, I had suggested to the team that handles the game core for ygopro, Dueling Nexus and Omega that we (Omega) provide pre-errata scripts to ygopro and in exchange they officially support Edison in the base game core, which would provide easy fixes for this and many other small issues, but alas, they seem uninterested in such.
Appreciate the (quick) feedback. Thank you.