With the start of Season 2, it is a good moment to highlight «breakpoints» that exist in the system and how you can benefit from them.
Upgrade Track Sources and Max Item LevelsThe first thing you'll notice when obtaining gear in Season 2 is that each item now belongs to something called «Upgrade Track». This track is a limitation on how high you can upgrade a given item. There are five different upgrade tracks:
Explorer — Upgradable up to 398 Adventurer — Upgradable up to 411 Veteran — Upgradable up to 424 Keystone +2 to +8 End of Dungeon Loot LFR Raid ItemsChampion — Upgradable up to 437
Keystone +9 to +16 End of Dungeon Loot Normal Raid ItemsHero — Upgradable up to 441
Keystone +17 to +20 End of Dungeon Loot Heroic Raid ItemsExplorer and Adventurer are tracks for open-world items, while the others come mostly from group PvE content like Raids or Mythic+. Mythic Raid items can't be upgraded.
Obtaining Shadowflame CrestsOnce you have obtained the items you want to upgrade, it is time to upgrade them. For that, you will need to spend Flightstones, which are farmable and obtained by virtually anything, world quests, rares, Mythic+, and raid bosses, all of which give Flightstones. However, you will also need to spend Crests, which have a weekly cap. You may obtain 150 Fragments of a given crest every week and 15 fragments will turn into a Shadowflame Crest. Below you can see a breakdown of the source of each crest.
Whelpling's Shadowflame Crest 300 Fragments cap instead of 150 LFR Difficulty Raid Bosses Mythic+ Dungeons below +6 World quests, Treasures, and other activities in Zaralek Cavern Fragments Sold by SpinsoaDrake's Shadowflame Crest
Normal Difficulty Raid Bosses Mythic+ Dungeons between +6 and +10 Read more on wowhead.com