The variable energy shield left a deep impression on Tom.
Don't be fooled by the fact that the Havilah Civilization's unique energy shield technology didn't seem to have much effect under the attack of his own Unified Force Field, only reducing the damage rate of the warship from 99\% to about 94\%, which is only a 5\% difference. Don't forget the power of the Unified Force Field.
That was a killer move that Tom had accumulated over hundreds of years, at the cost of the lives of 3.5 billion clones, and that could only be used with the help of his own special abilities. It was very likely that it was unique in the entire Milky Way, or even the entire universe!
With such a deadly move that ordinary civilizations wouldn't even dare to dream of, increasing the survival rate of one's own warships by 5\% is already quite impressive, even unbelievable.
