Do keys drop even if you play the same champion?
I know that you can earn 1 box per champion
Is that the same with the keys too? or with the same champion you can earn keys again and again?
I know that you can earn 1 box per champion
Is that the same with the keys too? or with the same champion you can earn keys again and again?
You can earn multiple fragments in the same Champ but there is a monthly maximum
Yes
Champions do not play a role in key fragment drops - only wins, time, and keys you've earned recently. The fragments drop on a pseudo-random system that increases as the number of fragments you've had drop in the last month increases. The formula is 80%/(#of frags earned).
So at the beginning of the cycle (if you play frequently) you will get a cluster of frags from your first wins and then it will spread out to every 5ish wins and slowly decrease from there.