Forma del dragón

Unless some effect explicitly says otherwise, a creature that can’t attack you can still attack a planeswalker you control.

If you life total was above 5 at end of turn, then you lose life to make your total 5. If it was less than 5, you gain life to bring it to 5.

It sets your life total at the beginning of the end step of every player’s turn, not just your own.