>>47664569You do realize Cloyster can still use Life Orb, right?
In fact, Life Orb provides far more consistently against checks Cloyster otherwise would need to rely on a 41%/10% chance of occurring. Here is a pastebin of Calcs where the extra damage has a better chance of beating a Pokemon than the chances to flinch with Skill Link or Ice Shards
https://pastebin.com/i94HVNrXThe reason why King's Rock is banned is because Cloyster can just cheese past counters/checks like Tapu Fini, Toxapex, Bisharp, Suicune, Melmetal, and most Scarfers that otherwise would consistently counter/check Cloyster.
