1. block in the following manner:  crag puca blocks nova chaser.  cemetary puca blocks hamletback goliath.  shapesharer blocks fire-belly changeling.

2. tap all land.  20U 8G

3. make crag puca flip p/t.  19U 8G

4. make fire-belly changeling into a cemetary puca by way of shapesharer.  17U 6G

5. make cemetary puca a crag puca by way of shapesharer.  16U 4G

6. make the new crag puca flip p/t.  15U 4G

7. make the new crag puca a cemetary puca by copying the previously-fire-belly changeling.  14U 2G

8. make the original crag puca a rustrazor butcher (which is now 2/1 first strike due to previously flipping the p/t).  13U

9. allow first strike damage to resolve.  nova chaser is dead, we are at two life.

10. use cemetary puca's triggered ability to make it a copy of the nova chaser (which is now 2/10 due to previously flipping the p/t).

11. allow normal damage to resolve.  hamletback goliath tramples in for 1 damage.

you survive the attack with one life.