The twins have done a bunch of stuff throughout the story to alter peoples’ courses of action. I rattled off the most important ones, but there are other instances throughout the story. As big as altering memories so people forget that they saw the twins, to as little as making Ten think a door has already been opened so he’ll walk into it and bash his face. (That one was just for their own amusement.)
I want to be clear that they can’t do big stuff though. They didn’t make Kiva and Raj fall in love. All they did was help nudge them along. Same as with Ten and Kiva’s friendship. Ten and Kiva became friends of their own volition, but the twins definitely helped raise Ten’s interest and determination to become Kiva’s friend, and helped influence Kiva to be a touch more tolerant of Ten than she otherwise might have been.