Show and Tell + Ethersworn Canonist

[Solthos]

Opponent casts Show and Tell, he plays Hive Mind, I play Ethersworn Canonist. Can my opponent cast pacts after the Hive Mind drops or does Canonist's effect already take effect?

[Koby]

Nope.

As soon as both permanents are put into play, Show and Tell finishes resolving. Ethersworn Canonist looks to see if a player has played a non-artifact spell (Show and Tell player indeed has) and prevents that player from casting additional non-artifact spells.