I love the varying emotions conveyed from embarressed (Byakuren, Mokou), Mildly annoyed (Marisa, Ichirin,Reisen) Flabbergasted (Reimu, Futo, Mamizou) Kinda bothered but not really (Miko, Kokoro, Koishi) What ever emotion Doremy is trying to express and PISSED (Shimmy, Kasen, Jo'on)
Although it's not because Tenshi has undergone special training, she is extraordinarily strong and tough. This toughness is to the extent that she cannot be pierced by Sakuya's knives.This seems to be an effect of heavenly peaches, when one eats them, it forges one's body to one's convenience. heaven doesn't have normal food apart from the peaches, so all Celestial probably eat these peaches and strengthen their bodies.