Here is the full list of all 30 Iron Mandate achievements.
Finish the tutorial by defeating the Guard
Rise above the citadel and defeating the Knight
Reach the limits of the world of the mortals
Reclaim what is rightfully yours
Claim the throne in less than 7 minutes
Claim the throne in less than 6 minutes
Claim the throne in less than 5 minutes
Last 45 seconds against the beam Juggernaut
Last 45 seconds agains the flame Juggernaut
Last 45 seconds with nothing but a terrain generator
Find the best arsenal to defeat a flaming Juggernaut
Find the best arsenal to defeat a beaming Juggernaut
Find the best arsenal to defeat a seeking Juggernaut
Balance a ball for 45 seconds
Hunt down a Juggernaut with lasers
Hunt down a Juggernaut with volleys
Win the breach fight
Defeat the Juggernaut swarm
Maintain the high ground
Lay waste to your enemies with dragons
Lay waste to your enemies with ultimates
Lay waste to your enemies with prisms
Defeat the guard with only one hit point
Defeat the knight with only one hit point
Defeat the duke with only one hit point
Defeat the king with only one hit point
Complete the rehearsal
Truely reclaim the throne