Not taking into account the Gods or versions of characters that are featless (like 5C Mel):
Strenght:
1. Noon Mael
2. Noon Escanor
3. AM Mel
4. Indura Derieri/Monspeet
5. Chandler/Cusack
Wild with Full Throttle should be up there too, but I'm not sure where to place him.
Magic (Raw Power):
1. King (Fully Grown Wings)
2. 4C Mael
3. Goddess Eli
4. Ludoshel
5. Sariel/Tarmiel
Mel and Zel using their OG Magic should probably be on this list too, but since we still don't know the full extent of their magic, I'll wait until I see more of it. OG Gowther could probably be here too, but he's also pretty much featless.