Good to know. Focussing on Kai/Rhea now.Also, I recommend if you only use 5* monsters(like Jailer) to reroll because the game is currently inclined on using some 5* heroes for insignia transmutation. You should remember faith rerolling using gold and 5* heroes is random so you could end up with still a shitty faith.
This I already do.Last reminder. I suggest you keep your phoenix hatchlings. Don't feed them to 3 or 4* heroes. 5* only get 1-2% from 1-2* monsters and 5% from 3* when you fuse them. The constant 20% when feeding phoenixes to 5* is big and will let you upgrade them much easily.