Froslass is a unique Pokemon, as she is the only Ghost-type Pokemon who can set up Spikes. With this combination, she can set up entry hazards while blocking Rapid Spin at the same time. What also separates her from other supporters is her blistering Speed coupled with Taunt, which effectively blocks attempts to keep Froslass from setting up while preventing opposing Pokemon from setting up their own entry hazards. Froslass also works well on hail teams, as Substitute, Thunder Wave, and Snow Cloak will surely annoy the opponent. Despite all of these advantages, Froslass isn't well equipped to handle the OU metagame due to her common weaknesses and the prevalence of priority moves, especially Bullet Punch. Nevertheless, Froslass is a great choice for offensive teams that require Spikes at the beginning of the game without resorting to the slower Skarmory or Forretress.
Froslass is a good lead in today's metagame, as her base 110 Speed and immunity to Fake Out and Explosion allow her to fare well against some of the more commonly seen leads. Opposing leads who attempt to set up entry hazards are stopped by Taunt, enabling Froslass to set up her own entry hazards.
Spikes is the main move in this set, causing residual damage whenever the opponent switches Pokemon. Taunt serves the same purpose as in the previous paragraph, while Destiny Bond works well with Taunt to take down the opposing Pokemon. Ice Beam rounds out the set, allowing you to 2HKO Aerodactyl, Azelf, and Hippowdon leads.Team Options & Additional Comments >>>
While Froslass can make a reliable lead, you cannot forget about her ability: Snow Cloak. This set combines Snow Cloak and paralysis to cause plenty of stress for your opponent. For example, with the opposing Pokemon paralyzed and hail falling, Froslass will only be hit by a 100% accuracy move 60% of the time. If you can confuse the opponent, either through Froslass running Confuse Ray or some other means, then that brings the chance down to 30%, allowing Froslass to either set up Spikes or attack with her STAB move with near impunity.
Substitute allows you to stall until the opposing Pokemon misses an attack. Thunder Wave slows down the opponent so Froslass can set up a Substitute before it can move and can prevent the opponent from attacking. It also prevents opposing Pokemon who try to use stat up moves from sweeping due to their lower Speed. While Froslass has a Substitute up, she can set up Spikes, which, alongside hail, slowly wear down the enemy. The last slot is for either attacking or more utility if you feel it is necessary. Blizzard takes advantage of the hail due to the accuracy boost it receives. Ice Beam is there for the extra PP and accuracy outside of hail, but is weaker. Taunt is an interesting choice on Froslass, as it prevents opponents from setting up, such as opposing Calm Minders. It also prevents Forretress and Skarmory from setting up entry hazards but prevents Froslass from dealing any damage.Team Options & Additional Comments >>>
Froslass has an excellent Speed stat, which when combined with access to Spikes, makes her an excellent lead. Although she is generally slower than Aerodactyl and Azelf, this set attempts to remedy that by using a Choice Scarf. With the Choice Scarf, she can either cripple the opposing lead or proceed to set up several layers of Spikes.
Trick is a powerful move on this set, as it cripples your opponent's lead. If Froslass is up against Aerodactyl or Azelf, she can Trick the Choice Scarf and lock them into either Taunt or Stealth Rock. If it's a bulky lead, then you've deprived your opponent of a useful late-game tank. Spikes is to take advantage of bulky leads as they switch out if they're locked into Stealth Rock or a weak attacking move. Destiny Bond gives you a free kill when you die, potentially allowing Froslass to cripple one Pokemon and KO another. Ice Beam is a reliable STAB option for 2HKOing Azelf and Aerodactyl leads, along with unboosted Dragon-type Pokemon. Furthermore, it ensures Froslass doesn't become useless if opposing leads Taunt her.Team Options & Additional Comments >>>
When considering a Hidden Power type, remember that an unresisted STAB Ice Beam does slightly more than a 2x Hidden Power. Hidden Power Fighting may be used to combat Tyranitar, 2HKOing 0 HP / 0 SpD neutral natured Tyranitar with Stealth Rock down. Unfortunately, it does leave Froslass with a 30 Speed IV, which means she loses to other base 110s like Gengar. Hidden Power Ground can be used for Heatran, as it has a 79% chance of OHKOing 0 HP / 0 SpD negative natured Heatran with Stealth Rock and one layer of Spikes down. Hidden Power Grass can be used for Swampert, 2HKOing the 252 HP / 0 SpD neutral natured MixPert set. Hidden Power Fire snags an OHKO on any unsuspecting Forretress and Scizor who try to Pursuit, but also leaves Froslass with a 30 Speed IV. Thunderbolt allows you to hit Water-types who resist Ice Beam along with Skarmory, although Starmie would be hit harder by Shadow Ball due to its weakness to Ghost-type moves.
Froslass can also use an offensively oriented set, composed of Ice Beam, Shadow Ball, Thunderbolt, and a Hidden Power or Trick if Froslass is holding a Choice item. However, Gengar is generally a better Pokemon for this, as its higher Special Attack allows it to deal more damage. Froslass can also use a set with Trick to debilitate her opponents and then begin to set up Spikes, but her low defenses make it hard to do so effectively.
As for support options, Light Screen may be used, but Froslass is generally too frail to continuously set them up. Block can be used along with Destiny Bond and Taunt to force a kill, but it is a one-time deal. Snatch can steal a Substitute or stat boosts from your opponent if they try to set up in front of Froslass to avoid Destiny Bond. Swagger can be used over Confuse Ray on the Snow Cloak set in order for the opponent to deal more damage to itself if it hits itself, but its 90% accuracy and the +2 Attack boost it gives to the opposing Pokemon can be dangerous.
Checks and Counters
Froslass's main counter is Tyranitar, as Sand Stream immediately removes any hail falling on the field, while he can threaten Froslass with Pursuit, Crunch, or Stone Edge. His ability causes a sandstorm, gives him a Special Defense boost and allowing Tyranitar to shrug off any Ice Beams Froslass may try to use. Scizor and Metagross can both come in on Ice Beam or Shadow Ball and bypass Froslass's Speed with Bullet Punch or catch her switching out with Pursuit. Snorlax can Pursuit or Crunch Froslass, depending on if she stays in or not. Also, any faster Taunter can force Froslass to attack and stop using support moves as Substitute does not block Taunt. Slower Taunters have to watch out for Thunder Wave.
As a lead, Azelf and Aerodactyl both shut her down, as their higher Speed coupled with Taunt prevents Froslass from setting up any Spikes. Although Froslass can 2HKO them with Ice Beam, they will have still managed to set up Stealth Rock. On the Snow Cloak set, however, Swampert is a good counter to Froslass because of his immunity to Thunder Wave and neutrality to Blizzard and Ice Beam. Swampert can either Roar away Froslass or attack her with Earthquake or Surf.
Froslass's success is tied to her Speed. If you can inflict paralysis upon her, Froslass will be effectively neutered. Barring that, Bullet Punch, Shadow Sneak, and Sucker Punch all have priority, bypassing Froslass's impressive Speed and scoring super effective damage. Stealth Rock also prevents Froslass from switching in too many times. Since her defenses are not that impressive, hitting Froslass with any neutral attack will cause severe damage to her, most likely causing her to die from another switch-in.