Theme Decks aka starter decks are pre-constructed decks of cards made to allow players to get in on the new set without having to purchase enough packs to construct a full deck
Suddenly a one-damage ping deals three, a Lightning Bolt swings for five, and your big red dragon hits like a freight train
If you run one of these commanders, you may need to have a Rule 0 discussion with your pod before you play your deck: Generally, these are commanders that most players don't want to play against at, say, Bracket 2, as Commander Format Panel member, Gavin Verhey puts it
It is useful especially when you want to have Lucario
Odric, Master Tactician Odric, Master Tacticians ability can prove extremely useful in a properly built deck