He can technically Split his Abilities into different branches through his current Control ability, mixed with his Domain.
By this, he means that he can use one of several effects of the ability and not use it as if it were a single body, with no ability to split.
His Ice Power is an ability that is, by default, like this. It is not centralized. His Ice can freeze Reality, and for this, he offers different, essentially independent ways to do so.
For example, Frozen Time or his Frozen World. There is also the Ice Transformation and other abilities belonging to the Ice Power, but which can be used independently of the core ability.
But most of them don't work that way.
When Matthew realized that he could split his abilities through Control, he immediately thought of his Unique Ability.
Although he could activate the 'vanish' partially, thanks to the same ability, he could not do it as well as with his ice power. That's why he tried to split it.
