Here is the full list of all 19 Heavenstrike Rivals achievements.
Get a ★★★★★ unit.
Train a unit.
Get a ★★★★ unit.
Complete Story Mission 21.
Complete Story Mission 43.
Complete Story Mission 62.
Complete a Strike Mission.
Complete a Daily Mission.
Get a ★★★★★★ unit.
Promote a unit.
Reach Level 10.
Reach Level 20.
Reach Level 50.
Reach Level 100.
Be promoted to Drake Division.
Be promoted to Chimera Division.
Be promoted to Basalisk Division.
Be promoted to Archangel Division.
Be promoted to Sky Ruler Division.