密文词频分析

https://quipqiup.com/

XMVZGC RGC AMG RVMG HGFGMQYCD VT VWM BYNO, NSVWDS NSGO RAO XG UWFN AF 
HACDGMVWF. AIRVFN AII AMG JVRRVC-XVMC, FYRBIG TVIZ ESV SAH CGQGM XGGC 
RVMG NSAC A RYIG TMVR NSG SVWFG ESGMG NSGO EGMG XVMC WCNYI NSG HAO 
FVRG IVMH JARG MVWCH NV NAZG NSGR VTT NV EAM. OVWM TIAD YF "CV NSYF 
YF CVN JMOBNV RO HGAM", YC IVEGMJAFG, EYNS WCHGMFJVMGF YCFNGAH VT 
FBAJGF, FWMMVWCHGH XO NSG WFWAI "TIAD" NAD ACH JWMIO XMAJGF. GCUVO.

开始尝试rot13，无果
丢到 https://quipqiup.com/ 自动分析

得到明文

broken men are more deserving of our pity, though they may be just as dangerous. almost all are common-born, simple folk who had never been more than a mile from the house where they were born until the day some lord came round to take them off to war. your flag is "no this is not crypto my dear", in lowercase, with underscores instead of spaces, surrounded by the usual "flag" tag and curly braces. enjoy.

由此可得flag{no_this_is_not_crypto_my_dear}