Question: gbf how to get crystals?
Answer: Complete most quests for the first time (50 each) ... 
Host and defeat a raid boss for the first time (50 per difficulty)
Earn trophies (5-50)
Monthly activity bonus (up to 500 a month)
Daily Bonus reward (450 every 15 days)
Event daily missions (50 each)
Unite and Fight betting (varies)