Something I wondered about Killian, Ink Duelist was how this card's cost-reduction ability interacted with spells that interact with creature cards or spells and not creature permanents.
Spells like Empyrial Armor and Crib Swap can both target a creature permanent on the battlefield which allows these spells to cost less to cast if Killian is on the battlefield under your control while casting and targeting a creature with those spells.
However, something like Animate Dead targets a "creature card in a graveyard," so is it implied that with Killian on the battlefield under your control, Animate Dead costs less to cast because it targets a "creature" anyway?
How would Killian interact with Venser, Shaper Savant regarding returning a target spell to its owner's hand if the spell targeted is a creature spell?
Does a spell targeting a creature not have to be a permanent on the battlefield for the spell to cost less with Killian out?