Su-35 not MiG-35
Yes, the MiG-35 is a thing, and you are right about the differences between the -29 and -35.
But this twitter post says it's a Ukrainian MiG-29 vs. Russian Su-35
Yes, both top of the line fighters in the MiG and Sukhoi lines are both numbered 35 and derived from earlier types.
MiG-29 --> MiG-35
Su-27 --> Su-35