I was looking for the answer to this myself - for weapons in PVP, you need 3 kills without dying to make a diamond lance with stasis weapons. I'm not sure if this is happening bc I wasn't paying attention before to see if 3rd kill would create a lance. I will check soon and edit to update. From the Dec. 2021 Twab https://www.bungie.net/7/en/News/Article/50880 Behemoth Diamond Lance Increased fragment slot allowance from one to three. Now spawns a Diamond Lance upon: Killing PvE combatants with Stasis Weapons. Killing three players with Stasis weapons without dying. Killing an enemy with a Stasis ability. Shattering an enemy.