Ballista Watcher // Ballista Wielder

The activated abilities of Ballista Watcher and Ballista Wielder are completely independent of one another. For example, if you activate Ballista Watcher's ability targeting a creature and then it becomes night, the targeted creature can still block this turn. Conversely, if you resolve Ballista Wielder's ability targeting a creature, transforming it into Ballista Watcher won't allow the creature dealt damage this way to block.