[@Letter Bee] Lucas' power reminds me a whole lot of Gremmy Thoumeaux's power from Bleach. He could realize anything he imagined as long as he could concentrate on it, and if not it was cancelled out. Of course, he was near invincible. 

There's a nifty trick regarding this type of near-omnipotent character, and it's that this specific limit of concentration can be bypassed by simply imagining say two copies of himself. They're exactly him, a fruit of his imagination. Their only goal is to imagine various things without losing concentration while the first one only has to concentrate on keeping them in existence. 

Cool concept aye?