While Chansey was once completely outclassed by her older sister Blissey, Eviolite has transformed her into one of the most bulky Pokemon in the entire game. Eviolite boosts both of Chansey's defensive stats by 50%, making her a fantastic mixed wall. The only downside to holding Eviolite is that it forces Chansey to lose out on precious Leftovers recovery; however, this is essentially a non-issue, as with an efficient EV spread, Chansey is still able to take hits better than Blissey ever could. As if all this weren't enough, Chansey is able to act as an amazing team supporter thanks to Wish's new mechanic, which heals teammates with 50% of the user's max HP. Since Chansey's HP stat is tremendous, she can pass massive 352 HP Wishes to any Pokemon on her team, keeping them completely healthy throughout the duration of the match.
However, it isn't all good news for the Egg Pokemon. Chansey is still severely hindered by her downright-terrible base 35 Special Attack stat, forcing her to rely upon Seismic Toss and Toxic to deal damage to opposing Pokemon. This means that Ghost-types with Substitute, especially the ever-dangerous Gengar, will be a tremendous problem for her to take on (and to a lesser extent, Pokemon who can utilize 101 HP Substitutes). Additionally, while Chansey is ridiculously bulky, physical STAB Fighting-type attacks, such as Terrakion's Close Combat, will still take her down in a flash. Overall, Chansey is an amazingly bulky wall who can take almost any attack thrown at her with aplomb, so you should utilize her as such.
Due to her amazing overall defensive abilities, Chansey is by far the sturdiest Wish user in the entire game. The Egg Pokemon is capable of passing 352 HP Wishes to her teammates; this will completely rejuvenate the health of any Pokemon with up to a base 105 HP stat (provided said Pokemon lacks EV investment in HP).
In the second slot, you must choose between Protect and Softboiled. Though Protect allows Chansey to stall more effectively with Toxic—while simultaneously allowing her to heal herself with guaranteed Wishes—Softboiled can be used if you want Chansey to be able to heal her own HP on the spot. Seismic Toss is utilized so that Chansey can reliably deal damage to all opposing Pokemon who aren't Ghost-types, while Toxic enables Chansey to slowly wear down foes over time. Toxic is especially good since it works wonderfully in tandem with Wish and Protect, allowing Chansey to drain the HP of opposing Pokemon much more effectively.Team Options & Additional Comments >>>
Chansey's stat distribution is seemingly perfectly built to abuse Counter. Thanks to the Egg Pokemon's huge HP and Eviolite-boosted Defense, little physical dents in Chansey will quickly be bounced back to create huge holes in the opponent's physical attackers. Here's how this set works: switch Chansey in on a physical attacker who won't be able to OHKO her right off the bat. Then, when the opposing Pokemon uses a physical attack, Chansey can bounce the attack straight back for double damage, hopefully netting a KO in the process.
Softboiled is the preferred recovery move on this set, as Chansey's moveslots are much more limited than they are on the first set. However, Wish can be used if you want to play a bit more dangerously with Chansey. Chansey can use Wish before the opposing Pokemon attacks her—or if they can't 2HKO her—to restore 50% of her health while still bouncing back physical attacks with Counter. While this strategy seems far superior to simply using Softboiled, Softboiled lets Chansey restore 50% of her health on the spot, making it the more reliable, consistent option. Seismic Toss and Toxic are used so that Chansey can still damage special attackers. Seismic Toss is the better option against offensive special attackers, such as Latios, while Toxic is more useful against defensive ones, such as Jellicent.Team Options & Additional Comments >>>
Like most Normal-types, Chansey has an extensive movepool. Thunder Wave can be used over Toxic for paralysis support, but beware that by ditching Toxic, Chansey loses her main weapon against walls, especially defensive Ghost-types. Stealth Rock can be used over Toxic or Protect if you lack a Pokemon to set it up on your team. Heal Bell is a possibility if you want a cleric; additionally, it works well alongside Wish, as a combination of the two can essentially fully heal any teammate. Chansey has access to a wide variety of special attacks, but her terrible Special Attack stat makes these moves poor options in any situation.
Checks and Counters
Ghost-types who carry Substitute and can outspeed Chansey are outstanding counters to her, because she cannot touch them since Toxic and Seismic Toss are her only effective means of dealing damage. Taunt users, such as Whimsicott, can screw up Wish Chansey pretty badly. Gengar is a particularly worrisome Taunt user, as it is also immune to Seismic Toss and Toxic. Despite Chansey's titanic defensive capabilities, physical Fighting-type attacks will still deal catastrophic damage to her, though few are capable of OHKOing the Egg Pokemon. Wobbuffet can completely ruin Chansey through Encore, allowing at least one Pokemon on your team a free turn of setup.