Here is the full list of all 11 Spellbreak achievements.
Unlock 6 class afterglows
Unlock 12 talents
Revive a total of 20 teammates
Win a Battle Royale
Unlock 1 class afterglow
Fall into the Fracture
Revive a teammate
Place in the top 10 in Battle Royale
Exile 5 players in a single match
Exile 1 player
Exile a player with an elemental combination