Here is the full list of all 44 Chronicle: RuneScape Legends achievements.
Win 50 games in any mode.
Open 10 booster packs.
Draw at least 10 cards from effects in a game.
Complete a smithing skilling challenge.
Win any game with Ozan.
Win any game with Linza.
Win any game with Vanescula.
Build at least 3 custom decks.
Win a least 3 games in a single dungeoneering run.
Complete a magic skilling challenge.
Start a dungeoneering run.
Craft a card in the collection.
Get promoted to the silver league in ranked.
Reach rank 1 in the ranked bronze league.
Gain rising star in ranked.
Complete an attack skilling challenge.
Complete the silver tier in solo.
Play 10 games in any mode.
Build a custom deck.
Open a booster pack.
Unlock all the Legends in the game.
Complete the bronze tier in solo.
Win any game with The Raptor.
Have at least 5 base attack in a game.
Have at least 10 armour in a game.
Win any game with Ariane.
Complete the tutorial.
Have a weapon with at least 8 durability.
Have at least 30 gold in a game.
Have a weapon with at least 10 attack.
Have at least 10 base attack in a game.
Complete an entire dungeoneering run.
Win 500 games in any mode.
Get every legend to at least level 25.
Get promoted to the gold league in ranked.
Get promoted to the diamond league in ranked.
Complete the gold tier in solo.
Have at least 75 armour in a game.
Have a weapon with at least 20 durability.
Have a weapon with at least 20 attack.
Have at least 15 base attack in a game.
Have at least 150 gold in a game.
Open 50 booster packs.
Win any game with Morvran.