These are definitely good starting points.
The killz volume would be good if you want the instant death player is destroyed. This could be placed below your lava and set to move along with your Lava mesh.
The pain causing volume will require more setup, but will give you better results if you don’t want the player to to die instantly. You will need to setup how the pain causing volume affects the player through BPs to tell it that when the player is inside the volume the health is reduced.
I hope this helps!
Tim