Step 1: What is asked.
We need the winner of the Women's Premier League 2025.
Step 2: About the WPL.
The WPL is India's top franchise based women's cricket tournament, with strong Indian and overseas players.
Step 3: The 2025 final.
The season ended with a final between the top two teams, which gave a new champion.
Step 4: The champion.
Royal Challengers Bengaluru won the final and lifted their first ever WPL title in 2025.
Step 5: Remove others.
Delhi Capitals, Mumbai Indians, and UP Warriorz did not win this season.
Step 6: Conclusion.
So the WPL 2025 champion is Royal Challengers Bengaluru.
Answer: Royal Challengers Bengaluru