Loki and Zoro, highlights of the chapter.
Luffy being Luffy. And Loki is slowly becoming more and more interesting. He has that Elbaf warrior pride and certainly has some twisted motive behind destroying the world.
From the available info I can conclude that Shanks placed Loki in Elbaf to wait for the right moment.
As we know, Shanks dont play around when someone hurts his friends (Elbaf citizens). So, Loki is not really evil. Maybe Herald was framing him to be the bad guy for some reason (world government involvement).
Perhaps, they were trying to recruit Loki. If the Prince joins, then he can influence other giants to follow the footsteps. World Government were actively recruiting giants through various underhanded means. Just a speculation. I wont be surprised if this was the main reason behind all of this.