Nine times out of ten, when people hear the name Sigilyph, their immediate response is, "that annoying Aztec bird". It's easy to see why, too, as it has a moveset designed to frustrate its opponent. Psycho Shift, Calm Mind, Cosmic Power, and Magic Guard make Sigilyph a surprisingly sturdy foe, and one that will often have players pulling their hair out in their attempts to break it. The only thing standing in the way of an imminent sweep is its typing; its common weaknesses to Ice-, Electric-, and Rock-type attacks, average bulk, and a lack of an immediate offensive presence give many avenues for opposing players to exploit its limitations. But once the cards are in place and Sigilyph's enemies have finally fallen, there is little that can stop its cosmic rampage as it threatens to boost its defenses to the heavens and unleash its Stored Power.
Sigilyph has all of the right tools to be an effective sweeper. Magic Guard negates its Stealth Rock weakness, Psycho Shift transfers burns with the use of Flame Orb, and it has two great moves with which it can boost its decidedly average offensive and defensive capabilities. Stored Power reaches a frightening maximum of 240 Base Power with six Cosmic Power boosts under its wing, enough to dent even stalwart special walls such as Snorlax.
However, it is also said that with great power, comes great responsibility. With that in mind, using Sigilyph effectively requires a lot of good planning and switching. The idea is to wear down its numerous enemies by passing off burns, and then pivoting to a corresponding check until its counters have taken too much damage to pose a legitimate threat. Air Slash is an even greater help in this area, as it allows Sigilyph to ward off some of its checks, such as Heracross and Houndoom, even without boosts, and defeat its Dark-type enemies who are immune to Stored Power. Using this foolproof method can put Sigilyph in a position to sweep that begs the query of 'when' rather than 'if'.Team Options & Additional Comments >>>
Thunder Wave, Whirlwind, and Psycho Shift can all go hand-in-hand to make Sigilyph an effective status platform and support Pokemon, but make it complete fodder for Pokemon such as Roserade and Shaymin, who can heal status effects. Though Sigilyph can attempt to use an offensive set with Life Orb, Alakazam does it much better with its higher Special Attack and Speed. Ice Beam is good for hitting Zapdos, but that's about it.
Checks and Counters
Sigilyph is nigh unstoppable with a few boosts under its belt, but it will take some time to acquire them. Strong special attackers with STAB on one of Sigilyph's weaknesses will put an early end to it. Chandelure is unrivaled in this regard, as it steals a free Flash Fire boost from Sigilyph's attempts to burn it, and cuts right through its defenses with Shadow Ball and a ridiculous Special Attack stat. Houndoom also stops most Sigilyph cold, as it is immune to all but Air Slash, and it can use Nasty Plot to keep up with Sigilyph's boosts, KO with Dark Pulse, or Pursuit it on the way out. Other problematic Pokemon are Zapdos and Abomasnow, who can both deal significant damage to Sigilyph even after a defensive boost, and offensive Fire-types such as Victini and Darmanitan, who are immune to burn and can break through Sigilyph when equipped with a Choice Band.
Sigilyph is usually at its most vulnerable when momentum is not on its side, and it isn't given an opportunity to set up. If KOing Sigilyph right away isn't an option, phazing it out can act as a temporary solution. Notable users of phazing moves such as Suicune, Arcanine, Empoleon, and even the less common Altaria, can force it out without dreading the burn too much. Packing Taunt or Substitute, and a boosting move, will shut down its attempts to garner momentum, and a team made well with its tricks in mind should not fear it.