system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU][Endgame][Spoilers] Finally watched endgame and have a few questions

Spoilers obviously you have been warned!!




>!Why did Tony snapping hurt him as much as it did? He wasn’t wiping out/returning half of everyone, only dusting Thanos’s army. Also why couldn’t he use it to heal himself/someone else resurrect him?!<

>!At Tony’s funeral we saw all the major characters but there was one I couldn’t identify, the person standing behind Bucky but in front of Danvers. I know that’s not a great description but I don’t know of any online clips to reference.!<
gpt
Using the infinity stones for any mortal is dangerous and basically to much power. It wasn't the effect that hurt him, it was wielding the power of the stones that did it. 

And that person was the boy that helped Tony charge his suit in IM3.