If enough -1/-1 counters are put on a creature you control at the same time to make its toughness 0 or less, Host of the Hereafter’s last ability will see all of the +1/+1 counters it had when it died as well as the -1/-1 counters it had, and the same number of each of those types of counters (plus any other applicable counters) will be put onto the target creature.