Hey raino,
Ok so in this situation the returning player can either step around to use their forehand on the backhand side to quickly attack the long fast serve with a tospin,however this does require good speed and footwork to get there quickly. They can also retuen using the anti loop rubber trying to either drop the ball with a very soft return short over the net by taking the pace of the ball using a soft contact and relaxed grip. Or you can hit through the ball quickly with the anti loop trying to aim for the serevers crossover to limit thier chances of a strong attack and aslo taking their time away.
I hope that helps and anything else feel free to comment back on here!