Both Sasuke and Madara's Sharingan awakened/evolved after they

What does Madara Uchiha mean when he said that Sasuke had the same 'straight comma Sharingan' as he did? - Quora

Mangekyou Sharingan

The Mangekyou : r/Naruto

Is the Sharingan destined to die out? With sasuke and sarada only being the ones left, eventually the sarada line with dilute? Unless sasuke gets hoes? : r/Naruto

Boruto: 10 Powers Sasuke Still Has After Losing His Rinnegan

naruto - Did the writer mention that 2 Tomoe Sharingan can instantly awaken into Mangekyou Sharingan? - Anime & Manga Stack Exchange

If Madara can seamlessly switch from Sharingan to Rinnegan and vice versa, why didn't he casted Izanagi when Black Zetsu stabbed him before his transformation into Kaguya began ? : r/Naruto

Naruto: Top 14 Strongest Mangekyo Sharingan Users, Ranked

Sasuke otsutsuki, Anime Omega Wiki

Naruto : 5 Forgotten Facts About the Sharingan, by Septionime

Sasuke & Sarada's FORBIDDEN SHARINGAN POWER UP IS COMING-Sarada's Future Eternal Mangekyou Sharingan