Offalsnout

If a creature spell cast with evoke changes controllers before it enters, it will still be sacrificed when it enters. Similarly, if a creature cast with evoke changes controllers after it enters but before its sacrifice ability resolves, it will still be sacrificed. In both cases, the controller of the creature at the time it left the battlefield will control its leaves-the-battlefield ability.

If you're casting a spell "without paying its mana cost," you can't use its evoke ability.

When you cast a spell by paying its evoke cost, its mana cost doesn't change. You just pay the evoke cost instead.