I  play as cipher as my 1st walkthrough for 2 hours only, and note that cipher actually can be  quite a good controller, with excellent spell even in level 1 to 'charm' enemy and make group of enemies 'blind'. However,  I cannot find much information about how the state of 'blind', ' daze', ' slow', 'flank' affect the combat. Can anyone please help?

I know they have entries in the in-game encyclopedia, but you're probably looking for percentages and stuff like that? I don't know if they're mentioned in those entries.

Very helpfully, if you hover over the terms you're wondering about in the spell descriptions, it will provide a breakdown of what those status effects do.