Honkai: Star Rail Eidolon for Trailblazer

Eidolons enhance Character’s abilities or provide them with new passive bonuses. Each Character has 6 Eidolon upgrades with each Eidolon upgrade providing a different bonus.

While for the majority of characters the only way to get your hands on their Eidolon is to obtain their dupes (via Warps), there are a few exceptions with the main character - Trailblazer - being one of them. In case of the MC, instead of pulling his/her dupes you need to obtain some special items:

• 

  Shadow of Destruction
  - for Physical Trailblazer
• 

  Shadow of Preservation
  - for Fire Trailblazer

Here's a list of places where you can find all 6 Shadows of Destruction for your Physical Trailblazer:

1. Herta Space Station - Prologue reward,
2. Jarilo-VI - Main Story reward,
3. Trailblazer Rank 19,
4. Trailblazer Rank 30,
5. Internal Purchase Officer on Herta Space Station,
6. Underground Shop on Jarilo-VI.

Overall, since all of those items are available quite early in the game, you will be able to max your Physical MC Eidolon within the first few days of playing.

Here's a list of places where you can find all 6 Shadows of Destruction for your Fire Trailblazer:

1. Jeweler's Pagoda on The Xianzhou Luofu (you can get 4 Eidolons from there).
2. Main Story on The Xianzhou Luofu (you can get 2 Eidolons from there).

Below's video shows the location of the shop: