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