This is the first item i made and now the mitic afix dont work 
i convert the ring or keep it?Cuz i dont have more obsidian
what do you mean dont work the mythic affix (Effective).
Effective almost the same as ignore resist affix.
About the Obsidian do you mean you put a wrong affix on it?
well that’s fine just keep your right you might use it in your future build.
Well ignore resist replace efective and i dont want one afix that does nothing in my build but i dont wanna convert the ring cuz i dont have more obsidians to make other xD
Anyway…What are the best mitic afix for rings on a rogue? Sorry for my bad english :'v
So, just remove Ignore Resist. 
Ignore resist and mythic 'effective ’ have different formulas so it should work together.
I put unity in my ring
No, I dont think so, Because when you put the affix ignore resist whit effective, in game the word efective doesnt appears anymore 
Ignore Resist does what it states: ignores resists.
Effective simply renders all of your attacks effective, therefore giving you a damage boost (25%, I believe).
They do work together, though I’m not sure how practical they are combined.