[OVERVIEW]
Unlike the all-out offensive Mega Pokemon like Evolutions such as Diancie, Charizard Y, and Kangaskhan, Metagross is held back by its poor offensive typing and the low base power Base Power of its STAB moves. It gives free momentum to the opponent's Steel-types, especially Aegislash, and it can be stopped by common Intimidate users, including Landorus-T. It's also pretty useless after a paralysis or burn being paralyzed or burned, though unlike Diancie or and Charizard, (AC) (Which one?) it has the bulk to gut ride out temporary field conditions such as Tailwind and Trick Room. However Moreover, with its good defensive typing, high base Speed, and fantastic stats all around, Mega Metagross is still able to serve as an effective speedy attacker, pivot, and utility check to offensive Pokemon such as Keldeo and Shaymin-S. It's not forced out too easily, except specifically by Aegislash, and it can come in without much difficulty and threaten to deal major damage on offensive Pokemon or potential switch-(AH)ins. While the "big three" mentioned above may provide immense power, they require a lot of support; Metagross, with its high Speed and Steel-type numerous (Don't want it to sound like resisting Steel is a major attribute) resistances, provides both some power and some support and is often a great choice for teams not built around a Mega Pokemon.
[SET]
name: Mega Physical Attacker
move 1: Zen Headbutt
move 2: Meteor Mash / Iron Head
move 3: Hammer Arm / Ice Punch / Substitute / Bullet Punch
move 4: Protect
item: Metagrossite
ability: Clear Body
item: Metagrossite
nature: Jolly
evs: 4 HP / 252 Atk / 252 Spe
nature: Jolly
[SET COMMENTS]
Moves
========
Metagross's most important moves are its STAB options. Zen Headbutt is a given; it is one of only three physical Psychic attacks and the only one Metagross can learn (What does it hit? Give specific targets.). Meteor Mash is Metagross's strongest attack, (RC) and has a chance to boost its Attack and make it even more threatening. Iron Head can be used over Meteor Mash for its greater accuracy and 30% chance to make the foe flinch, but for a tradeoff in power it has lower Base Power. This drop is noticeable in at least one common instance: Meteor Mash OHKOes standard Kyurem-B, but Iron Head does not. Protect is important for safely Mega Evolving to reach Mega Metagross's higher base Speed, (RC) and also lets it for stalling out field conditions such as rain or and Trick Room.
The final moveslot has many possible options. Hammer Arm is a powerful option that lets Metagross damage Steel-types not named besides Aegislash at all, OHKO Hydreigon, (AC) and have a chance at OHKOing Mega Kangaskhan, but it must be used cautiously thanks to its speed Speed-lowering effect. Ice Punch can be used for the sole purpose of OHKOing Landorus-T, but Metagross's STAB moves will still do hefty damage at -1, so it's not vital. Substitute lets Metagross avoid status moves from the likes of Thundurus, Rotom-W, and Amoonguss, (RC) and lets it soak up a single hit if set up safely. It also blocks Intimidate, which makes using Substitute on the turn it Mega Evolves a cool strategy—Landorus-T's can't Intimidate is useless on that turn because of Clear Body, and it can't Intimidate it's also useless on the next turns because of Substitute. Bullet Punch is rather weak, but it can be very useful for hitting specific threats. It should only be considered on teams that totally lack priority or are uncomfortably weak to Mega Diancie. If necessary for a team's function, Metagross can drop one of its STAB options for one of these moves, although this is not recommended.
Set Details
========
It may seem that Metagross's ability does not matter before Mega Evolving, as you it almost certainly will be Mega Evolving as soon as possible. However, this is untrue—-(AH; HTML codes don't show up on Markdown) Clear Body is an incredibly strong ability as it renders Metagross immune to the weakening effects of Intimidate, making it awkward futile for Landorus-T and other Intimidate users to switch in. The EV spread is simple but effective. Attack and Speed receive full investment to best suit Mega Metagross's stats and ability. A Jolly nature lets it take advantage of its great Speed tier. There are some alternate EV spreads that can be run; 16 HP / 240 Atk / 252 Spe lets you Mega Metagross survive a Sucker Punch from Adamant Life Orb Bisharp and makes Substitutes with 76 HP, which can only be broken by Adamant Landorus-T's U-turn with an absolute maximum damage roll. Another possible EV spread is 72 HP / 252 Atk / 184 Spe with an Adamant nature. This bulkier spread is best used on semi-Trick Room teams. It outruns neutral base 101 Speed opponents Pokemon normally, and after a Hammer Arm, it will be slower than opposing Rotom-Wash, so Mega Metagross will outrun it under Trick Room. The Adamant nature gives it a high chance to OHKO Heatran with Hammer Arm and a small chance to OHKO 4 HP / 0 Def Mega Charizard Y with Zen Headbutt, although most Mega Charizard Y are bulkier, (AC) so you must be cautious.
Usage Tips
========
If your opponent has a Pokemon which that Metagross needs its Speed to dispatch, such as Keldeo or Hydreigon, then it is best to Mega Evolve as soon as possible, even from when leading, so that you don't need to waste a turn on Protect when you need Metagross ready to switch in. Otherwise, (AC) you can wait until you need it to attack to Mega Evolve, sometimes waiting on purpose so that Clear Body can protect against an block (subjective change) Intimidate. Metagross has the bulk to switch in multiple times throughout a match, which it uses to its advantage. Typically, Metagross is best brought in when it can score an OHKO, and then it just uses the appropriate move. Since Because Metagross's main prey, Keldeo, is typically a cleanup Pokemon, Metagross often comes in after a teammate faints, though its good bulk also lets it come in on weak or resisted hits. Once Metagross is no longer able to OHKO something, or once it's threatened by, say, a Pokemon such as Talonflame, you switch it back out, and it can comes back in again later. Metagross hands Aegislash momentum on a silver platter gives Aegislash insane amounts of momentum (save colloquial stuff for articles), as does non-Hammer Arm Metagross with Heatran, so if your opponent has one, you will need to play ballsier more recklessly with Metagross than usual, utilizing double switching among other tactics and the like. Substitute Metagross plays somewhat differently from three-attacks, coming in on Pokemon like such as Amoonguss that allow it to set up a Substitute and only switching once both its Substitute is broken and it cannot KO anything.
Team Options
========
Between its incredible offensive presence and its innate defensive capabilities, it's very difficult to find a team that won't benefit from Mega Metagross. In many cases where a team is not built around a Mega Pokemon, Metagross will be the best fit thanks to its supportive capabilities. Metagross's best partners are Pokemon that can beat Steel-types and bulky Water-types, as these two groups are perhaps its biggest threats. Hydreigon is an example of an excellent partner here, as it threatens all of Aegislash, Jirachi, Heatran, Ferrothorn, and Rotom-W. Metagross greatly appreciates any type of speed control, including Tailwind, Thunder Wave, and even Icy Wind, from partners like such as Talonflame, Thundurus, or and Cresselia. This allows it to ensure it outruns the opponent foe and lets it get past some Choice Scarf users like such as Landorus-T. Politoed makes for a nice partner for those who want to use Rain, as it negates Metagross's Fire weakness and gives it allows Swift Swim partners to remove fast attackers and Choice Scarf users. Like all offensive Pokemon, Metagross enjoys redirection support from the likes of Amoonguss and Togekiss to let it avoid attacks and continue its rampage. Wide Guard supporters like such Aegislash are in a similar boat, similarly (again, if this was an article, I'd allow it) blocking Earthquakes and Heat Waves. When building around Metagross, other Pokemon to add are those who that enjoy what Metagross has to offer. Hydreigon is again a great partner, as Metagross removes the Fairy-types and Fighting-types that Hydreigon fears, and together the two hit on both sides of the attacking spectrum both specially and physically (Never say "spectrum." But b/c this is your first analysis in awhile, I won't murder you.).
[STRATEGY COMMENTS]
Other Options
=============
Rock Slide is an option to hit Mega Charizard Y, Talonflame, and Volcarona, but the move does pitiful damage otherwise. Grass Knot is available to hit Suicune and Mega Swampert while getting a Tough Claws boost, although it forces a nature that lowers a defensive stat. Magnet Rise gives Metagross an immunity to Ground, (RC) and, (AC) when combined with Clear Body, (AC) makes cripples Landorus-T cry, while also allowing Metagross to firmly beat Earth Power users such as Shaymin-S, Mega Diancie, and Kyurem-B. Refresh is an option to turn the tables on opposing Rotom-W and Thundurus by removing the status conditions they inflict, getting Metagross back in the game. Hone Claws is Metagross's only reliable option to boost its Attack and makes its STAB attacks 100% accurate. Finally, it gets Earthquake. While it does hit the Steel-(AH)types that otherwise wall Mega Metagross, Earthquake does not get STAB nor a Tough Claws boost and as a result is incredibly weak as a result, barely doing more to Heatran than Hammer Arm.
Checks & and Counters
=================
**Intimidate and Burns**: While an unevolved Metagross can avoid the former with Clear Body, these are very effective ways to neuter Mega Metagross. Landorus-T and Gyarados are significant threats with Intimidate and the ability to cripple or KO it (although Metagross can run Ice Punch for Landorus-T). Sableye, maximum Speed Talonflame, (AC) and bulky Rotom-W are the best candidates for burning Metagross; the former two outrun it while the latter can take a Zen Headbutt.
**Typing Advantage**: Bisharp, Heatran, and Aegislash all resist Metagross's STAB attacks and hit it for massive damage in return. Mega Charizard Y, Talonflame, and Rotom-H threaten with boosted Fire attacks. Choice Scarf Landorus-T is a major threat because it outruns, Intimidates, and then uses Earthquake; it should be noted, (AC) however, (AC) that Earthquake does not OHKO Mega Metagross. Darkrai, Greninja, and Mega Gengar are notable for their ability to outspeed and hit Mega Metagross with super effective attacks, with the latter even trapping it for a guaranteed revenge kill.
**Speed Control**: Because a large part of Mega Metagross's viability hinges on its high Speed, it is very vulnerable to speed control. Tailwind from the likes of Suicune or Talonflame lets slower partners get the jump on it and its teammates for a few turns. Thunder Wave from Thundurus permanently slows down Mega Metagross, letting even Aegislash outrun it. Icy Wind from Pokemon such as Cresselia can slow it down for a short while while also dealing some chip damage, but this can be reset by switching out. Trick Room makes an opposing Mega Metagross very vulnerable to attacks from the likes of Mega Camerupt or and Aegislash. Cresselia is the Trick Room setter than can most easily set it in front of Metagross, although other viable setters exist such as Jellicent.