STPVR WTSEP KQ VRE ATVREP UA FYDE QDLXTFDEP
DARTH VADER IS THE FATHER OF LUKE SKYWALKER
it’s a simple substitution cipher. most common letter in English is
E, and most common word is THE. with one 3 letter word in your
cipher text, ending in “E” which is very common in your cipher
text, VRE->THE is a decent guess. R and S are also common, and P
is also common in your text, giving a good guess that it’s R or S.
“KQ” suggests a common two letter word, and Q appears a couple
times so not an uncommon letter; KQ probably is “OR” or “IS”. Put
all that together and you have
__RTH ___ER IS THE __THER __ ___E S______ER
It’s not a long drive from there to the answer; “A” and “T” are
pretty common, probably one of them a vowel and one a common
consonant (L or N), and a few shots in the dark (plus I just
watched Rogue One) and the answer shapes up quickly thereafter.