Is this supposed to say "Phyresis?"

yes yes it is fixing... fixed

Reminder text automatically italicises, so you don't need to add stars around it; doing so makes it no longer italics.

Pretty cool mechanic. Lets you use whichever "life total" you want to pay phi costs :)

The cost of 4 is sensible to avoid dropping the huge dragons excessively early in the game.

I would be tempted to make this more universal and change it to "If you would pay life, you may instead gain a poison counter for each 2 life you would spend, rounded up." (Or something like that.)

^^^ I like that idea a lot. Changed