The Brazilian's dramatic strikes in the 90th and 91st minutes against City last season snatched City's ticket to the final out of their grasp.
Madrid clinched victory in extra-time at the Santiago Bernabeu to progress and went on to win the competition for a record-extending 14th time.
In contrast, Pep Guardiola's side are yet to get their hands on the trophy.
The forward has won every trophy possible during his short time at Real Madrid, completing the set with the Copa del Rey after the 2-1 win against Osasuna on Saturday.
Rodrygo netted inside two minutes and struck the winner after Lucas Torro pulled one back for the minnows from Pamplona.
"Nobody knows just how far he can go," said Real Madrid coach Carlo Ancelotti after Rodrygo's brace.
"He's a very elegant player, whose movement is amazing and he scores goals. He's progressing spectacularly."
Madrid thrive in cup competition and Rodrygo, signed from Santos in 2019, is in his element under that same pressure.
He pulled Madrid level in the quarter-finals of the Copa against rivals Atletico to force extra-time, a memorable win on Los Blancos' road to victory.
In Europe, all five of his Champions League knock-out goals have come against English teams.
Rodrygo fired Madrid into the semi-finals with a brace at Stamford Bridge against Chelsea, and admitted he feels he has a unique connection with the competition.
"I always say, I have something special with the Champions League," Rodrygo said.
"I want to keep going. Of course, I also want to score more goals in La Liga, but I watched the last game and I played really well, but the goals didn't come.
"Today, two goals came. I want to keep scoring in the Champions League."
It started with a hat-trick on his European home debut, in a 6-0 rout of Galatasaray.
Rodrygo, then 18, became the second youngest ever player to score a Champions League hat-trick, behind Real Madrid legend Raul Gonzalez.
In 21 Champions League appearances in the past two seasons, Rodrygo has scored 10 goals. He has scored the same number from 63 La Liga games in that period.
His starring role in Madrid's comeback against Manchester City was as a substitute, but his form in 2023 has made him a key figure for Ancelotti.
Deployed on the right wing and occasionally behind the striker, Rodrygo offers consistent genius. He is a superb dribbler, using flicks and tricks when needed, and finishes lethally.
On the other wing, his compatriot Vinicius Junior often draws the attention with his speed and flair, which sometimes means Rodrygo's quality goes under the radar.
While Vinicius' quality is admired but his behaviour heavily criticised, Rodrygo is generally viewed in Spain in a more positive fashion.
The forward dedicated his second cup final goal against Osasuna to a child with cancer.
"I dedicated it to Nacho, a kid I visited at a place that cares for children with cancer," said Rodrygo.
"I went over there to pay them a visit and give them a gift or two. He asked me to make the 'I' for Ignacio if I scored, so the second goal was for him."
It is not guaranteed that Rodrygo will start against City. Ancelotti sometimes plays Fede Valverde out wide in big matches, taking advantage of his work-rate, although in his current form and with his thirst for silverware, it will be hard for the Italian to leave out Rodrygo.
"This was a title I wanted to win because it was the last I was missing and at 22 years old, I've won everything possible," Rodrygo said after Madrid's triumph in Seville on Saturday.
"But I want to keep winning a lot more."