How to activate Vasto Lorde and other second forms?

[RAfflik]

This is probably a stupid question, but I can't find any information on Google. I've noticed on YouTube that when you die, you turn into Vasto Lorde, but for me, Ichigo just dies and nothing happens. As for the other characters i'm even more confused how to activate their second form.

[@Shinigani No KageTTV]

you have to get sublimation full bar to get vasto lorde i had trouble understanding at first, but just but stay alive until then an die then come back as him with 2 bars!

[JackieTheDemon]

Fill Sublimation bar then get KO'd (If you take enough konpaku damage at once, it will fill the bar)

Does not work on mugetsu.

[@Shinigani No KageTTV]

i didn't know that about mugestsu thank you jack!