Puzzle #03

To correctly answer the puzzle tell Tabs the KEYWORD used for this ciphertext.

BSCWARS KI FMS JWUJBTY RNQKCAS TFLGR! KV UDJ HYY XFFXYEY TIYQ QSEXUSU CCNWOIS AK GTCQSQV ZUHHZIZ, MCILAW, OEX RFBKUED CE NTJ SRMFJFE MQFPFUDI. CLL AKTZWUFZ YIGWG RLQ KFFG ZNBV NA XWO, VGY HYYDJG LMGFZCS ETAVIZJ WE BQWS LHFNZ KBQD YZWW ZG FOF TT KBQ XOT. QQ ZGLUXQM YUHJ GFGQYVZHS TB KBQ YJ RHP BS YUHJ OCF FMSJY SFAVM MWCLHP YCF. CR DCL QMSH KI FFYV IGY O SIAP XLMF QSK NTJ VVUP QWSLMWWRH AW OTNUAS JBUKHYIXISI EZTK. NBMYG PIGW BRGQ GM KBQ BOP? HUHS KI YJSK SAZ!
-HYY EUWVF

Don't know much about ciphers? Here are a few common ones (and yes, it is one of them on the list for Classical)