I thought about makeing hero concept on heinz doofenshimrtz but not to sure who should be his friends maybe hiro since he is robotics paradogy and doofenshimrtz known due to his intors even then i will have missing friend since i am not sure with each another charther doofenshimrtz can befriend
I can see a Hiro-Doofenshmirtz friendship since in later seasons of Phineas and Ferb, Doof was more of an anti-villain(meaning that he has a pinch of sympathy within him), and he can work well with a Hero not related to pure villainy. One of the scenarios in their friendship could be Doof and Hiro working together to make an Anti Creep-inator that wards of Creeps in the City quickly. I mean, Zurg befriended Hiro.
Maybe a second friendship with Megavolt? They’re mad(in a mad scientist way)with inventions.