Darkness Pokmon can be weak to Fighting and Grass-type Pokmon, depending on whether they are also Dark or Poison-types and the specific card
For four mana, you can sneak this 3/3 Ninja with double strike onto the battlefield , meaning six damage is going to land on your opponent unless they have a counter or removal
As far as combat tricks go, this one rules
The Commander Admiral Beckett Brass is leading your charge into the fight, wielding with it the powerful ability to give all your pirates a +1/+1 buff at all times
Loxi: I don't really like this card for group hug unless you have ways to manipulate the counters on it yourself
The best Dragon commander in MTG is The Ur-Dragon excels for classic tribal value, Tiamat offers precise tutoring and combo setup, and Miirym dominates with explosive board states