I read that ion Color brilliance in 10A could lighten your hair without brassiness. But I dont understand how it would lighten your hair without bleach?
It's basically the same thing. At least, it does the same process. It's as damaging generally. the difference is, it has the toner/colour in it already so it will tone out the brassyness as it lightens.
At least when you use bleach you can vary the strength in many ways. With these dyes, you can only change it with the level peroxide you use.