Jerren, Corrupted Bishop

Whenever Jerren, Corrupted Bishop enters the battlefield or another nontoken Human you
control dies, you lose 1 life and create a 1/1 white
Human creature token.
{2}: Target Human you control gains lifelink until
end of turn.
At the beginning of your end step, if you have
exactly 13 life, you may pay {4}{b}{b}. If you
do, transform Jerren.