The Matabele are his pawns.

He wanted to aim a blow at ME; and THIS was the way he chose to aim it." "Do you think he is capable of that ?" I cried.

For, in spite of all, I had still a sort of lingering respect for Sebastian.

"It seems so reckless--like the worst of anarchists--when he strikes at one head, to involve so many irrelevant lives in one common destruction." Hilda's face was like a drowned man's.
"To Sebastian," she answered, shuddering, "the End is all; the Means are unessential.

Who wills the End, wills the Means; that is the sum and substance of his philosophy of life.