TR-15 is the first challenging training mission that you will encounter during the Arknights. It is designed to teach players the return of deployment points.
How to make the return of points to an operative?
Simply select the operator you want to return, and select the “running man” icon (in the screenshot).
First put Plume (Vanguard) in position A.
Then place Fang (Vanguard) behind Plume in position B.
Now place Jessica (Sniper) in position C, facing left.
Return Plume before he dies.
These three heroes will be enough to keep the enemies from above.
There are several ways to pass this level, but the main thing is to return your deployment points to your operatives.
Returning Plume will give you enough points to place the Beagle (Defender) in position A.
Make a return to Jessica and Fang.
Place Amiya in position B.
You can also place the Hibiscus (Medic) in position C.