Here is the full list of all 34 Idle Champions of the Forgotten Realms achievements worth 1,000 gamerscore.
Completed Area 250 in any adventure or variant
Completed 72 Variant Adventures
Gained 1e40 Gold over all adventures
Completed 48 Variant Adventures
Gathered 10B favor with Torm
Completed 100 Free Play Runs
Gained 1e32 Gold over all adventures
Completed Area 200 in any adventure or variant
Completed Area 150 in any adventure or variant
Completed 50 Free Play Runs
Completed 12 Variant Adventures
Unlocked 9 event Champions
Defeated 1,000,000 Monsters
Gained 1e25 Gold over all adventures
Completed 10 Free Play Runs
Unlocked 3 event Champions
Defeated a level 100+ boss within 10 seconds of starting the area
Completed 4 Variant Adventures
Shot down 1,000 crows
Defeated 250,000 Monsters
Completed Area 100 in any adventure or variant
Gained 1e18 Gold over all adventures
Used Minsc's ultimate attack
Obtained a Shiny (silvered) loot item
Purchased and assigned a familiar
Unlocked an event Champion
Defeated 25,000 Monsters
Manually attacked monsters 250,000 times
Gained 100,000,000,000 Gold over all adventures
Completed the "A Brief Tour of the Realm" adventure
Defeated 2,500 Monsters
Gained 100,000 Gold over all adventures
Complete 250 Free Play Runs