OpenWRT Compatible Router
Install OpenWRT Firmware on your Router
Setup Luci Panel and spoof your bridge ARP
TIP - Isolate your PC ARP
Use 2 Routers (Just one need be OpenWRT Compatible)
OpenWRT Router to Cheating PC
Other Router to Other devices (Laptop, Phone ETC)
Disable Wifi on Cheating Router
This gonna make you have one ARP entry only, you cant spoof other device ARP and Riot use other devices ARP to flag your account