Riddlesmith
Scars of Mirrodin — uncommon
Creature — Human Artificer
Riddlesmith rulings:
2020-08-07: An ability that triggers when a player casts a spell resolves before the spell that caused it to trigger. It resolves even if that spell is countered.
2020-08-07: You draw a card and discard a card all while Riddlesmith's ability is resolving. Nothing can happen between the two, and no player may choose to take actions.