Does Yuma Lose His Black Trigger?

Yuma's father sacrificed his own life by giving up all his trions to make a Black Trigger. He then sealed Yuma's severed body inside the black trigger, which takes the form of a ring. Yuma was later revived into an artificial Trion body.

Does Yuma still use Black Trigger?

Yes, unless it's been retconned, Yuuma should be able to use his ring also through another combat body, as weird as that sounds; but his Black Trigger is a chaos of exceptions, so it would not be that weird.

What happened to Yuma Black Trigger?

Yūgo, finding Yūma's wrecked body, created a Black Trigger, a ring. He then sealed the body of the dying Yūma inside the trigger, substituting it with a body made of trion (with which his hair is white); thus saving Yūma. However, this took all of Yūgo's power, and so he turned to dust, crumbled and died.