The Shell Cipher (Challenge)

[Tiberius]

So I created my own cipher based on some historic ciphers with a few modern improvements. The cipher only works on uppercase characters (for simplicity at the moment). It also has a variable length key. Here is a short message that I have encoded using the cipher with a key:

NIY DXG IIRNSWTMGRW VUIN KKV VQPLR ZKLUJ NTYSI RBWQ WJPVL GTN WH YEUGV QLNNVVUY VC WEKYEFRG CNKXUFFVMYX MZAW LBJP PLJS DYKH NI QFEEGF FGYR FP AOKSY GM SFB XWFMKERQQSR XEXRMKUQQHECC DOLHVD ENJ KLHM RCZ JVIRUQPX CRRW RACJVRCN TGCO WEOZ ZTNBXWG Z IEDVVCAIOO PQ ANFEBOVOMQ UIEM HVDDPLR

The question is, can anyone work out the original message (I took it from a web article), and/or the key used? Even more points go to anyone who can reverse-engineer the cipher itself.

[Chuff]

I just gave myself a headache trying

[Shell B]

You think you have a headache? He sends me love letters that are ciphers. He thinks I am smart enough to figure this one out. He's wrong.

[Cinjin]

NIY DXG IIRNSWTMGRW VUIN KKV VQPLR ZKLUJ NTYSI RBWQ WJPVL GTN WH YEUGV QLNNVVUY VC WEKYEFRG CNKXUFFVMYX MZAW LBJP PLJS DYKH NI QFEEGF FGYR FP AOKSY GM SFB XWFMKERQQSR XEXRMKUQQHECC DOLHVD ENJ KLHM RCZ JVIRUQPX CRRW RACJVRCN TGCO WEOZ ZTNBXWG Z IEDVVCAIOO PQ ANFEBOVOMQ UIEM HVDDPLR

I deciphered it and ...

Wow, Tiberius, You really think highly of yourself! I mean you're clearly very smart, but I think it unlikely that we're all going to be you minions when your rule the world someday. And crowning yourself the King of America seems a bit over the top as well. Those are some crazy claims you're making but the one that takes the cake is that you were sent here by god to destroy all the stupids! I mean, I'm kinda all for it, but damn man!!!

(just bustin your balls brother)

[Tempus]

C'mon, this is too easy. I won't spoil it for the rest of you though.

[Rayaan]

I am thinking that one of the original words in there is "love."

[Tempus]

I am thinking that one of the original words in there is "love."

There's probably a "the" in there too, in my professional opinion

[Tiberius]

There is a "the". No "love" though.

[Jackalope]

So... basically what we have here is a challenge to decipher what amounts to a one-time pad cipher?

No thanks.

[Tiberius]

So... basically what we have here is a challenge to decipher what amounts to a one-time pad cipher?

No, this is in no way a one-time pad cipher.

If you want me to encrypt other things with the same key, or a different key, then just let me know.