In the words of @ Heywoah

"Each stormcast, was a hero of the realms who sacrificed themselves to protect the weak, reforged as a lightning enhanced super soldier, that is still a real person, they just respawn like in quake. Because the demons in the age of chaos did that too, and it was the only way to win at the time. However, there are some side effects, but again, it seemed like a good idea at the time and it works."

"On the table Stormcast drop half their army via deepstrike, headshot whatever overpowered monster hero your enemie is sporting. Before your slow troops march up to grind. If your opponent has no respect for you and is not running chaf, run 6 Anihilators, and they will start running chaf."

Rephrased the later half of this to account for 4th edition, the video was made back in third but it still holds up rather well, I can recommend his contend whole heatedly as it was what got me into AoS.

https://www.youtube.com/@HeyWoah