An oathbreaker cube.
(Rules for oathbreaker here: https://oathbreakermtg.org/quick-rules/ )

Cube notes:

Your deck must match the color identity of your oathbreaker.

60 card decks
Draft 4 15-card packs
For 4-person multiplayer play

The emblems represent “crowns,” cards you can draft to add to your Oathbreaker’s color identity.

Only one crown can be used per deck.

Basri=white
Jace=blue
Nixilis=black
Chandra=red
Garruk=green

Arlinn=two planeswalkers you’ve drafted now have “partner” each of them costs 2 more to cast, and has their own signature spell

Narset=choose a color to add
Venser=add the color of the next card you draft