Hello! The first time I played Ranked, Rainmaker was in rotation with Arowana Mall(and another stage I don't remember). I had the most amazing streak.
One rainmaker match I had on Camp Triggerfish was near the enemy spawn. My team bust the shield, and I grabbed the Rainmaker and went up to the wall with a teammate. The enemy team tried to get to us the other way around, but the teammate splatted them and used the 'C'mon!' message afterwards. Ended in a knockout :) I know it's not much, but this was before I had Splatoon friends, so I thought it was really nice.
About 2 months ago, I faced a Kraken and won(with the Aerospray RG)