Here is the full list of all 20 Spellweaver achievements.
Play 100 games.
Unlock all quest points on the World Map.
Win a game at 1 life.
Win a game by depleting your opponent's deck.
Win a game by having 40 or more life.
Win a game that lasted at least 7 turns, without receiving any damage.
Win a game after playing at least one card from each aspect.
Play 20 Ranked games.
Reach a rating of 1250 or more points.
Complete 5 Spellweaver Trials.
Reach 10 Wins in a Spellweaver Trial.
Win 7 Friendly or Ranked games in a row.
Complete 5 Epic quests.
Unlock the Spellweaver fame title. (Reach Fame Level 35)
Collect one copy of each Order card from Valiant Dawn.
Collect one copy of each Wisdom card from Valiant Dawn.
Collect one copy of each Nature card from Valiant Dawn.
Collect one copy of each Rage card from Valiant Dawn.
Collect one copy of each Dominion card from Valiant Dawn.
Collect one copy of each Corruption card from Valiant Dawn.