so what I'm looking for is a story I wanted to read some time ago...but can't finde the name of.

what I remember about the story is that the protagonist is an outsider, because in this world everyone has this ability or magic, except for him....

and it's not break blade

sry, that's all I can remember >.<

Iris Zero?

Reality is a momentary dream but a dream is a reality for an eternity.

I also think it's Iris Zero
If not, then maybe Mx0

Sounds like a familiar plot that could be the basis of a lot of series. Mx0 is the most popular of them though. Mx0 involves magic cards if that's ringing any bells.

Break Blade also fits. Its mecha and the machines are run with these special crystals that people control. The main character doesn't have the ability to use these crystals, but he finds an old golem that only he can use.

Shouldn't be Iris Zero, because only the younger generation has the ability. I can think of the one he might be referring to, but the name eludes me as well.