Harry came back because Voldemort had used Harry's blood to regenerate. The protection that Lily's sacrifice provided to Harry got redoubled and now ran in both Harry's and Voldemort's veins. Thus, when Voldemort cast the killing curse on Harry, it didn't work properly. It only destroyed the horcrux inside Harry.
Lily Potter sacrificed her life in order to protect her infant son, Harry from Lord Voldemort. This placed Harry under magical protection, so that when Voldemort cast the Killing Curse at Harry in turn, the spell backfired, leaving him unharmed (save for a lightning-shaped scar on his forehead) and Voldemort bodiless.
So it doesn't really matter that he casts aside both the Resurrection Stone and the Elder Wand- the point is that Harry owned all three Deathly Hallows simultaneously, and accepted death at the same time. He survives Voldemort's Killing Curse because he is the Master of Death.
How does Harry come back to life without using the Resurrection Stone? "Because Harry's body contained two souls: his own and Voldemort's soul shard. The killing curse kills the soul of the person it hits, but since Harry's body contained two souls, only one would be killed (one kill per spell).
Answer: Yes, she died on Mar 12, 1998 at the age of 105. Question: How old was Rose when she was on the Titanic? Answer: Like many fictional movie characters, the viewer is not given their specific age.
An immortal, undead, nocturnal 25-ish year old. As for Harkon, he looks either on the bad side of his forties, or the good side of his thirties.
Sesshomaru is 19 in human years and we and to know how old he is in demon years. Plug in the information we know about lifespan and you get his age. Use the ratio 2000 demon years/ 80 human years.