Next word "msaryf": m (13) → z (26) s (19) → f (6) a (1) → n (14) r (18) → e (5) y (25) → l (12) f (6) → s (19) → — not English.
t (20) → q (17) t → q b (2) → y (25) y (25) → v (22) q (17) → n (14) → — no. ttbyq msaryf mhkr
Could this be (each letter replaced by the one above on QWERTY)? Next word "msaryf": m (13) → z (26)
Let’s try :
I notice "mhkr" — if ROT13 → not obvious. y (25) → l
Reverse "ttbyq" → "qy btt" → apply ROT13: q (17) → d, y (25) → l, space stays, b (2) → o, t (20) → g, t (20) → g → ? No.