I think the best way that Ukraine could win this war at this point and the ultimate weapon against the Russian state is for Ukraine to convert to Islam. Become an Islamic republic and declare Jihad (A holy war) on Russia and Russians. Volunteers would stream in from the middle east to fight the Russians. Free Chechen and Dagestan people could join in the battle and an Islamic State of Ukraine can offer independence and full cooperation with the Islamic Republic of Chechnya and Ichkeria.
Ukraine already has a deep Muslim history, with Islam establishing itself in Ukraine in ancient times and a whole nation converting to Islam to fight off evil would see many mujihadeen come to join the fight against Russia.