He told them.
He did it in about six words and he did it on a live broadcast because there was no version of the next twenty minutes where he hid it from the four people relying on him.
"He's taken my mana. I'm at nine hundred."
There was a pause of about one second.
"Out of?" said Cillian.
"Three thousand one hundred."
"*Christ.*"
"Can he do it again?" said Ronan, which was the right question.
"I don't know. Probably." James backed off eleven metres and did not take his eyes off the man. "Nine hundred is fifteen Necro Blasts and that's the whole of it. I'm not going to have fifteen worth casting, so assume I've got about six in me that'll matter and I'm keeping the rest."
"For what?" said Finn.
"For the last two minutes of this, whenever that is."
He did the sum properly while he said it, because saying it out loud made him honest about it.
