Chansey

Chansey holds a strong niche in Ubers due to having the best Special bulk in the game; it's one of the best switch-ins available to special attackers such as Starmie, Alakazam, and particularly tier titan Mewtwo, taking a mere 21.4% maximum from its STAB Psychic and threatening it and its team with paralysis and sleep. It can also switch into Mew when healthy and threaten it with paralysis, as it survives all of Mew's regular attacks even at +2. It is one of the most reliable paralysis spreaders in the tier thanks to its access to reliable recovery and consistent entry points.

However, outside of threatening status, Chansey is extremely passive, as Seismic Toss can only 4HKO or 5HKO most foes, and it completely thuds into Rhydon, failing to break its Substitute. Ice Beam, meanwhile, does not particularly threaten non-Ice weak foes. Chansey can't even wall Mewtwo well in the long term, as it takes 44.2% minimum from a +4 Mewtwo Psychic; even with Light Screen it can easily be overwhelmed by Special drops and critical hits. Mewtwo can also use Self-Destruct or Submission to break through Chansey. It also can very easily run out of Soft-Boiled PP in longer games. Its low base Speed, which leaves it outsped by every relevant threat outside of Snorlax, Rhydon, and Slowbro, along with its physical frailty, notably being 2HKOed by Rhydon's Earthquake and taking 38.1% minimum from a Snorlax Body Slam, can at times make Chansey quite exploitable and a potential liability on teams.