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