Sep 4, 2021, 08:2909/04/21
I seem to get a couple a week from clan boss, and then pull some from tournaments/events here and there, and every so often complete the advanced quests book.
Of course, I could always buy them, but I exclusively just wait for CB drops. It took me a bit to book out my three leggos in my CB team for sure. I just try and focus only on the cooldowns of whatever champ I need next and not the ones in the vault.