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