Currently these two achievements can be two of the most difficult ones to get in a chaosball game. A lot of players I´ve spoken to have got these two achievements by co-ordinating 3 premade groups (often in higher MMR tiers) and hope to end up in the same battleground. However, this thread isn´t about how you achieve it, but rather:
How do I know how much damage or healing I did?
As it stands right now, there´s no proper way to track how much damage or healing I did to the chaos ball carrier. I can use combat metrics, but even then it´s very difficult for me to get a feeling for how far away I was from completing the achievement. My proposal is to add some kind of tracker under each achievement, that shows how much damage or healing you´ve done as best in any given chaosball game. Example:
Lets say I play 10 games of chaos ball. In my first game I manage to do 200k damage in total to the carriers and in the other remaining 9 games, I only managed to do 150k damage. If I then look at my progress for Chaos Champion it will tell me that I´ve 200k/450k. Same thing would go for the chaos Guardian achievment.
The Chaos Keeper has a way to track our progress, give us a way to track our progress for Chaos Keeper and Chaos Guardian as well.