There you work towards the same goal as the rest of the world with the same card pool, the results tend to get very similar, and you'll be rewarded for doing the same thing per archetype, ending up playing the same cards, doing the same thing
Plus, you need to put your opponents' life totals to zero anyways, so it's a win-win situation
Hand Disruption: Some Trainer cards force opponents to discard cards from their hand, disrupting their plans
"A Girl In The Gaming Store"
If you're new to collecting or uncertain, it's a good idea to get some targeted advice from an experienced collector - the staff at your local game store may be an excellent guide here
The clear theme post-rotation is that Amber is the format's defining ink, appearing in nearly every top-five deck paired with something different: Emerald for tempo, Ruby for aggression, Amethyst for card flow, Steel for removal