Keepsake
In application the Last Strike of Samsara was relatively simple. Having used it a couple of times Hao Xuan now understood its basic purpose. Once used with any other skill it would simply multiply that effect of the last strike of that skill and execute it four times instead of one, at full power.
Meaning Hao Xuan had just executed 'Sunder' four times at once.
The only other times he had used the Last Strike was as a last resort and without any combining it with another technique which still drained him of all Qi. And now after combining it with the only other skill that was more taxing on his body, it would not be an exaggeration to say that it could break him in half.
Even he might not be able to handle such a great degree of stress and backlash.