The set seems to have fairly high complexity, with a whole host unique cards, cards with many lines of text, and cards which are archetypes unto themselves
This omits cards like Mox Ruby as well as some interesting lands like Valakut, the Molten Pinnacle, but you dont need me to tell you those are strong cards in any red deck
Tesak, Judiths Hellhound Tesak provides +1/+1 counters for our Dogs and haste for every creature we have with +1/+1 counters on them
If you're a completionist after every Elsa card, there's no better place to start
Ashe, Princess of Darkness A good limited creature for artifact heavy decks with an aggressive tilt, Ashes size is acceptable, just watch that she trades with any 2 powered creature
The alternate commander, Celes, buffs characters with +1 counters if they come back from the graveyard