Li Changhe really misunderstood Luca, or perhaps there was a mistake in his understanding.
He thought that the contractor was able to save the injured Flamingo from the Divine Judgment Tactics and other [Players'] interference without leaving any trace.
That kind of strength would be terrifyingly strange.
However, after further understanding the contractor's ability, he felt that it was no big deal.
The reason a contractor can summon heroic spirits (Players) is because of the Omen Mark on their body.
It is said to be a mark appointed by a king and a qualification to participate in the Seven Kings War.
Only magicians with the Omen Mark can use those complicated arrays to summon heroic spirits (Players).
That's the origin of the name Omen Mark. When a chosen magician successfully summons a heroic spirit, the Omen Mark will be imbued with powerful magic, and it will transform into the Mark of the King.