Where to get runes???

[NoEyedDeer]

I have spent hours reading posts with runes in them and all they do is complain about the old system and exchanges.
There are no guides with Runes mentioned (according to the search engine).
Brutality rune comes with level. What are these other runes?, where are they?, how do we find them?
Is there a guide as to what is available at each level?
Very frustrating

[koevman]

If win tank from bag there is a very low chance to got heal/blood rune. I got more than 60 win and no rune inside(may be because i already got them). Other runes are with balens from mystery shop

[R24675921]

I've gotten blood rune from one of the chest even though I already have blood rune. It sucks now because heal and blood rune is so rare to get now; while back then you could get them easily.