A weapon, tool, character, or power that is iconic to a game or character, or that is famous/historically important in canon, that is actually a Pentultimate Weapon, or worse, a starter weapon that's replaced as soon as you find an upgrade. Usually a result of Gameplay And Story Segregation.
-Every starting weapon in FFVII, especially the Buster Sword. All characters are always pictured with their starting weapons. Every single one of those starting weapons is useless once you find a replacement.
-Ditto Soul Calibur.
-The Kingdom Key in Kingdom Hearts is a big-time example of this. In KH 2
, it's common to opt for older Keyblades instead of newer ones because of the specific stats and abilities offered, but the Kingdom Key still remains inferior to almost all others.
-Pikachu is an aversion. He was a useless iconic pokemon, so they introduced a hold item that turns him into a killbeast.
-Weapons in the Mass Effect series. Characters are shown in cutscenes using the Lancer assault rifle, Mantis sniper rifle, and Kessler pistol long after you've upgraded past them. At the end of Mass Effect 2, Shepard and his/her squadmates are shown using the Lancer assault rifle even if none of them are even capable of equipping an assault rifle.
-Dave Strider gets an upgraded version of a "legendary" weapon at the very beginning of his adventure, from his future self. He's still required to actually acquire it at the proper time because it's a Sword of Plot Advancement, but he refers to it as a "legendary piece of shit."