Just continue the metaphor, though maybe… backwards.

Get the ‘health bar’ down to zero.

Now you get a ‘boss stage transition’.

Now get the ‘health bar’ to zero again.

… repeat untill you are either dead or out of stamina.

Use a DMC/Bayonetta style additional scoring system for ‘style’ and ‘combos’, ‘damage’ done in a short period of time, sustained ‘damage’ output, etc.

… You follow?

You, as the ‘tutorial boss’, the goal is to ‘defeat’ you as many times as possible, with the highest score possible.

The game isn’t won when you uh… roll over, thats when the game begins.

You don’t just win, you go for SSS rank.

EDIT:

What is the French term for an orgasm, the ecstasy/dissociation afterward?

La petit mort, the little death.

… kill 'em with kindness, eh?