Hello all! About a month almost 2 ago i got myself a beautiful Mugo Pine from a store that have plants also. All seems to go well, I watered it when the soil was dry and a week ago the branches started to dry up and die. I cut all the dead ones and planted it in the garden, even tho i know is not yet the season of repot/replanted.
What could have been the problem? I have small hopes that he will recover...

Impossible to tell, the pictures of the tree seem fine. If it is the ground it will be ok, I would not have done that but it will not hurt. Now you will have to leave it for several years. You can wire and prune where it is.

I dont think he's doing well...

This is the part of the year when pines drops their old needles. Before dropping them they pull all the energy out of them to use for coming spring growth. The result is the needles tärning brown before they are dropped.

It looks perfectly normal to me. As long as this years growth is healthy there are nothing to worry about.

If you want the tree to look better right now you can remove the brown needles before nature does. I tend to leave them on. Just because this time of the year I do not spend much time on my trees. We have rainfall enough to just do a quick watering once a week and the repotting/styling season is not here yet. A short moment to rest before winter preparation starts.