Pick a card
Twisted Fate presents a random card which cycles through blue, red and gold for 6 seconds. Reactivating Pick A Card ends the cycle and modifies Twisted Fate's next basic attack to deal magic damage and apply a bonus effect, based on the card he selected.
So it's a basic attack like Talon/Rengar/Nasus with Q etc etc....so whiy Twisted fate can't have a critical strike using Pick a card?
I'm pretty sure about this but if i'm wrong just tell me and i'll check again with a 100% critical chance build