Yes a sacrifice, and yes a willing sacrifice, and yet also an active "actor" in his own death. The 19th century theologian Hugh Martin is particularly strong on this point, arguing against the common view of his time that the death of Jesus was ultimately a beautiful example of passive suffering. Hugh Martin insists that he was active as a priest (offering the sacrifice of himself) and that he was victoriously active at every point of his suffering. He was the only person not to have been merely a victim in his death -- martyrs can die heroically willingly submitting to suffering, but Jesus did more than that. Slightly echoing John Owen's point that "the death of Christ was the death of death," Hugh Martin has a turn of phrase along the lines, "He died death dead!" to try and express how Christ's death itself conquered death and triumphed over sin and Satan and hell.