The fight starts with a good switch.
U should use Phase Prism when Blade Dashing forward. I recommend a few things; use this two ability in a traight line, start Phase Prism when starting the way back with the Blade Dash, U should know the exact distance where U start from and where u will end up.
When U R in a dangerous situation, U can get some more secs of life by hitting heroes with Twin Blades and dashing trough enemy heroes with Blade Dash, or by dashing out from some spells like boss stun or blizzard.