Trainers » Boss's Orders | Trainers » Lysandre
Lysandre and Boss's Orders cannot be included in the same deck. This is similar to the rule that says Professor Juniper, Professor Sycamore, and Professor's Research cannot be included in the same deck.
Source: TPCi Announcement (2020-04-16), TPCi Rules Team (2020-04-30)
Trainers » Lysandre | Abilities » Omega Barrier
If my opponent's Active Pokemon has the "Omega Barrier" Ancient Trait, can I use Lysandre to switch one of my benched Pokemon with it?
If your opponent's Benched Pokemon has "Omega Barrier", then Lysandre's effect will be blocked. But choosing a Benched Pokemon without "Omega Barrier" will cause it to switch with the Active Pokemon because the Benched Pokemon is the target of Lysandre.
Source: TPCi Rules Team (2015-04-09)
Trainers » Lysandre
When playing Lysandre, who chooses which of the opponent's Benched Pokemon get brought forward?
The card says "Switch one of your opponent's Benched Pokemon..." so the person playing Lysandre gets to choose.
Source: Flashfire FAQ (2014-05-08), TPCi Rules Team (2014-05-08)