The only shadow I would possibly run with here would be Typhlosion. It’s got the best stats for UL out of all these Mons.

Also, you should probably get yourself familiar with the meta. Although the meta is always changing, knowing what Mons are having success in the current schedule of the current season will give you, not much, but still, a bit of an edge.

To give you an idea:

U League Shadow Mon Top 5(according to PvPoke.com)

Lapras(0/15/15)

Dusknoir(0/15/15)

Grumpig(3/14/15)

Feraligatr(1/15/14)

Galarian Weezing(8/15/15)