Kefka, Dancing Mad

You cast the spells one at a time, choosing modes, targets, and so on. The last spell you cast will be the first one to resolve.

Cards you choose not to cast this way (or can't cast this way) remain in exile.

If you cast a spell "without paying its mana cost," you can't choose to cast it for any alternative costs. You can, however, pay additional costs, such as kicker costs. If the card has any mandatory additional costs, those must be paid to cast the spell.