Tawek21
Villager
That sounds thematically good.EK should just have an extended list of spellcasting focuses that includes their bonded weapons.
My only caveat is game balance. I've designed builds for, but not actually played, an EK.
If real life play shows that an EK without restrictions to their spell focus overshadows other fighters, then the balance may need tweaking. But some table home-brewing this is how we will find out.