Ultimecia absorbing time because TC is absorbing not compressing.
TC is Magic.Ultimecia really wants to compress time even She realized Time is infinite because She really wants to compress time that's why She called that Magic, Time Compression Magic.
Scan Ultimecia it said Absorbing Time and Space NOT compressing.
This is the proof that TC is absorbing NOT compressing.
The Fact is this Magic actually absorbing time, simple as that.
If you cant comprehend it forget it.
You misunderstand the meaning of TC and Ultimecia's Motives.