The Revenge of Seven by Pittacus Lore (2014) HarperCollins 

The fifth book in the Lorien Legacies series in which Seven, Marina, has developed a new legacy, the ability to freeze any available moisture.  The cold that comes off of her is palpable.  She and Six and Adam, the true-born Mogodorian son of a general, fly south to a Mayan city and go into a temple that the Lorians altered into a sanctuary to hold the entity known as Lorien.  While they are en-route, John and Sam and Nine go to New York with the FBI to try to alter the outcome of the Secretary of Defense’s assurance to the United Nations that the Mogs are trustworthy allies.

En-route to the sanctuary, Adam bluffs his way past Mog scout ships that intercept him and instead gets an escort to the temple area, which is surrounded by a field that burns any Mog trying to get inside.  Once there, he announces that his father sent him to inspect their setup.  But the leader of the squad knows his father (whom he has killed) in fact, considers him a traitor.  When she drags him to the field to burn him, Number Six and Marina slip behind a gun turret and kill the Mogs, except for the leader, who runs off.  They get to Adam and because he has a legacy, he is able to follow them through the field.

The leader calls Setracus Ra urgently and lets him know the Garde are there and have entered the temple.  He tells her to make sure they don’t leave.  In the meantime, Five attacks Ra and is thrown out of the mother ship while it is still a long ways from the ground.

Four and Nine blast their way through Mog guards to find the Secretary looks like is almost dead.  Four prevents him from committing suicide and heals him.  He wants the Secretary to do the right thing.

Setracus Ra alights in front of the UN building and walks down a ladder with Ten, Ellie, his granddaughter, reluctantly beside him, announcing that they come in peace.  But the Secretary takes the microphone and announces that Ra is a monster intent on the destruction and enslavement of Earth.  Ellie manages to hurt Ra and his concentration make him lose the good looks he had applied to himself and reveal himself as he is.  But the charm he made between them still works and every attempt to hurt Ra reveals itself on Ellie instead.  Five figures this out and knocks first John, then Nine out of the way, but Ellie tells John how she is wounded.  Nine sees Five simply as a traitor and turns to fight him, angry because he prevented Nine from killing Ra (not knowing it would not have worked – only Ellie can hurt him).

Six and Seven and Adam enter the sanctuary, carrying Eight and the charms from their combined chests.  Lorien is awakened and brings Eight back to life for a few minutes so Marina and he can say goodbye.  But the entity is vague in how she can help with the Mogodorians.