Impossible, also referred to as High Level or HL, is content that becomes available after reaching rank 101.
Rank 100 Uncap
Players are initially capped to rank 100, but can raise the cap by completing the quest Twinkling Stars (20 AP) on Zinkenstill.
Twinkling Stars pits you alone against weaker versions of each Omega primal beast (around 3 million HP and 33%-50% attack power).
They have mostly the same mechanics as their Omega versions, so refer to the Omega strategies if you are unsure of how to defeat them. Completing the full chain of quests increases the rank cap to 150.
Most of the same content is available at HL, although there is some new content (Rose Queen). Mainly, HL versions of old content becomes unlocked, with new HL items dropping that are needed for many final uncaps.
HL content of note:
- Bahamut Weapon Coda upgrade (final)
- HL raids award Prestige Pendants
- Required to finish Class Champion Weapons
- Defeating HL versions of Omega primal beasts unlocks the final uncap for Omega weapons
- Fighting Rose Queen allows the player to obtain Rose Crystal Weapons, which are notable for their Unknown modifier and on-element damage reduction.
- Centrums from HL Omega raids are what locks quite a bit of content from players:
- Omega and Showdown Weapons cannot obtain their final uncap until you can obtain Centrums. Many 4★-capable Premium Draw weapons also need Centrums.
- Seraphic Weapons cannot be upgraded to SSR.
- Class Champion Weapons cannot be element-changed without elemental Centrums, locking out Row IV Classes in the process.
- The 5★ uncap for an Eternal requires elemental Centrums.
Rank 150 Uncap
Upon reaching Rank 150, return to Zinkenstill and complete the Whispers of the Stars quest. This questline will increase the Rank cap to 175. As you advance through these ranks, new Extended Mastery Perks unlock.