However, I also have a will

This is mostly focused on who Kaworu was as a character, from basics on the series to how he related with other characers. His overall role was brief, and can be best told through those he interacted most with and touched. This section can be best categorized as the "basics" section.

Introduction a bit of background for those who are new
Notes and Terms some vocabulary to familiarize
The Third Children the boy who fascinated him
The First Children similar, but not the same
Evangelion Unit-02 his combat skills and time spent in the entry plug

The reason I have existed

Kaworu's purpose and his destined fate, the ones which he chose not to follow, in the manga were very instrumental in SEELE's plan for humanity. But it turns out Kaworu himself really didn't care for any of it. This section covers his more pivotal role in the series, related to the overall plot.

SEELE, the Throne of Souls the old men who controlled him
Adam, the first Angel his soul's origins, and sealed fate
Third Impact humanity's fate, and his reason for existing

Then kill me with that hand

Death was not a freedom, but a choice. This is not just about his end, but the meaning it carried, and the impact it left. This section is less plot-centric and more of my commentary on his character. A bit of randomness can be found here as well.

The final choice the only liberty was for him to choose the method of his end
A reflection the impact he left behind
Doppelgangers other versions of him in different universes