The Mark X Armor was Tony Stark's tenth Iron Man suit and the third suit created after the Battle of New York. The Mark X was one of the first in a series of Iron Man suits created during a period of rapid development that led to the creation of the Iron Legion. It was destroyed when the Clean Slate Protocol was activated by Tony Stark.
The Mark X was called, along with the rest of the Iron Legion, to help Tony Stark and James Rhodes during their fight against Aldrich Killian and his Extremis Soldiers. During the course of the fight, a number of armors were destroyed, though they eventually managed to eliminate all of the Extremis Soldiers. At the end of the battle, the remaining suits that were not destroyed by Extremis Soldiers were destroyed when Stark activated the Clean Slate Protocol, including the Mark X. 
The Mark X has more weapon systems than any of the past suits. The extra repulsors on the suit's sides provide for an increase in flight, speed, and power. Its flight stabilizers on the suit's armor soles enable it to reach ever higher altitudes and fly 3 times as fast as the Mark IX. It has a new helmet and a better chest reactor than the past suits.
| Mark I • Mark II • Mark III • Mark IV • Mark V • Mark VI • Mark VII|
Mark VIII • Mark IX • Mark X • Mark XI • Mark XII • Mark XIII • Mark XIV • Mark XV • Mark XVI • Mark XVII •
Mark XVIII • Mark XIX • Mark XX • Mark XXI • Mark XXII • Mark XXIII • Mark XXIV • Mark XXV • Mark XXVI •
Mark XXVII • Mark XXVIII • Mark XXIX • Mark XXX • Mark XXXI • Mark XXXII • Mark XXXIII • Mark XXXIV •
Mark XXXV • Mark XXXVI • Mark XXXVII • Mark XXXVIII • Mark XXXIX • Mark XL • Mark XLI
Mark XLII • Mark XLIII • Mark XLIV/Veronica • Mark XLV • Mark XLVI • Mark XLVII • Mark XLVIII • Mark L • Mark LXXXV
|Mark I • Mark II/Iron Patriot • Mark III • Mark IV • Mark V • Mark VI • Mark VII|
|Mark I • Mark II|
|Spider-Man Suit • Iron Spider Armor|
|Iron Man Armor: Mark XLIX|