Here's how that will work:
You'll have to pass a sequence of immensely difficult Spirituality checks. If you do, this happens. If you fail, Tié can try again every month. If you leave the desert at one point, you get to come down here and choose again or choose to keep coming back every month to try again which will obviously create problems for other plot-lines you might be doing in the future. To make this happen, you'll need to succeed 3 of these checks. A Nat 20 will be treated as a normal success for these rolls.
I know this is kind of harsh rule-wise, but Tie is nowhere near the Spiritual enlightenment and the ability to bend pure life energy and chi to do something like this. It'd require (as you can see from the rules above) months of meditation and work for someone of his level.
Also, just to add little stakes, a Nat 1 makes you kill the tree by accident.
Do you agree to this?