AI Using Illegal Cards?

Firstofhisname419

Maybe this is common and I've only just now noticed, but does the AI often use illegal cards?  In Duets of Mana - Tears and Memories, Mu Yanling is using Rupture Spire from M19, but that's not allowed for us as it's out of standard.  How common is this?

jtwood

There is precedence. Fblthp uses Ball Lightning, for example.

https://forums.d3go.com/discussion/comment/905658/#Comment_905658

Ampersand

The restrictions are only on the player's decks, not the events decks. Challenge!

James13

Oliva uses Oliva, Ovirya Pashiri uses Kaladesh cards, Nahiri was using Kor Ally Zendikar cards, etc.

It's all appropriately thematic for encounters.