Ok first of all you will require the season pass at £11.99 uk Sterling or equivalent in US dollers ($14.99), to unlock Aquaman’s Movie Level Pack 1.
Once downloaded you will have a new playable level as seen below:
To acquire this achievement you will first need to complete the level on story mode, so that you unlock free play mode.
Load up the freeplay choosing Orm as your main playable Character.
As soon as you have loaded in to the level and can move your character tap the
button, as you will swop to your other playable character in another location.*please be aware you could void the achievement if you have all your Red Bricks ON, if you have Demolition Mode: ON turn this OFF before you carry on as you will destroy the throne as seen in below image*
As soon as you swop press
until you are Orm (Gladiator). Now walk into the back area passing King Nereus on his throne, you will come to another larger throne as seen below:
Walk upto the throne and as prompted tap the
button, you will now sit on the throne to hear that pop please see game Clip for Confirmation.
Sorry, this Game Clip has been removed
Then pop Achievement unlocked!**Just so your aware mine popped once the Harley Quinn save icon came up**