User blog comment:CrimsonWarden/Time Stop and Time Stop Countermeasures/@comment-26952857-20160910005822/@comment-26952857-20160910010446

now considering the time spell itself, when activated, characters with their time stopped can not be harmed in anyway, so why would ainz use it agianst shlltear

when he used it, against the tree, or gazef,, to harm them, he had to apply some delay magic on the magic he used ("fireball" in tree case, "true death" for gazef) and he times the activation of the spells exactly when the magic stop would end and characters can be harmed

in shalltear fight  timestop seem useless in that fight,  casting the offense magic directly without timestop and delay magic, would save him alot of mana, and he needed him mana as long as he could