as everybody stated, the cost for the cards activation is all cards in your hand and on the field, except for
Card of Sanctity of course.
this card is probably the only card were the controller it self isnt eligible to chain to it.
meaining, your opponent plays any of the following, your screwed.
Magic Drain
Magic Jammer
Null and Void
preaty much they play any of thouse cards and you just CED'd your self.
so why would
Serial Spell work with card of sancity?
lets see here, if we go in order of how stuff activates and when, I will activate
Card of Sanctity and as the cost to even activating i will remover all cards in my hand and on the field. okay, i am now field less and handless the only card on the field is card of sancity its self since its the card that just got activated.
IF a card gets negated to we get our money back for paying for such card? nope.
so that would mean, that if i play
Card of Sanctity there is no possible way for me to chain anything to it. not even Magic Mirror, which before I thought you could combine the 2, but the cost of Treasure Gift From Heaven makes it so you cant because quite simple, your screwed.
so preaty much with the conscept of costs and how you pay them and when you pay them you can see multiple combinations.
lets say its it was a card like, i dont know
Brain Control.
then you could
Serial Spell, but hence you have to have atleast 1 card in your hand to activate
Serial Spell.