Mega Aggron uses the Filter Ability, which reduces the amount of damage that it takes from Super-Effective moves by 25%.
Mega Aggron can be obtained by using the Mega Stone while Aggron is holding a Aggronite in battle.
Mega Aggron has yet to appear in a Spin-Off game as of writing.
Trading Card Game
Mega Aggron is a part of the Underused (UU) tier of competitive battling. With an extremely high base 230 Defense, great ability in Filter, and large number of resistances courtesy of its Steel typing, Mega Aggron is capable of taking hits very well. It has great support options in Stealth Rock, Roar, and Thunder Wave. Its nice base 140 Attack prevents it from being easy set-up bait, and this can be further bolstered if one opts for a Curse set that can make Mega Aggron very difficult to take down physically. However, Mega Aggron is not without flaws, as it has a lackluster typing before Mega Evolving and does not have any form of reliable recovery. As a Mega Evolution, it cannot hold Leftovers, further hampering its overall defensive prowess. Mega Aggron also suffers from a lackluster base 80 Special Defense that even when heavily invested in does not hold up very well against strong special attackers, and its low Speed forces it to take a hit more often than not when its on the field.
Mega Aggron is also a viable option in the Overused (OU) tier of competitive battling. Due to its typing, huge Defense stat, and ability in Filter, Mega Aggron is capable of handling some big threats in the tier such as Mega Metagross and Mega Altaria. It also has access to some great support moves in Stealth Rock and Thunder Wave. Unfortunately for Mega Aggron, it suffers from having no form of reliable recovery and having a huge opportunity cost as a Mega Evolution when there are many more Mega Pokémon that are arguably much better than Mega Aggron.
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