Thrasta, Tempest's Roar is an impressive Legendary Dinosaur from Modern Horizons 2 that has us examining some interesting new lines of ability text.
Let's go over this card line by line. The first thing to consider is how difficult Thrasta is to cast. With 12 cmc but a powerful cost reduction ability, we'll need to build our deck to maximize our ability to cast her early.
The interesting thing to note about this ability is that your opponent's spells also reduce the cost in the same way that Storm works. What are some cheap/free ways in green to cast a bunch of spells? Manamorphose, Burning-Tree Emissary, and Mishra's Bauble come to mind. We need to cast three total spells before casting Thrasta for a very attractive price of 3 mana.
To go further down the blitz theme, we can dip harder into red and play cards from the Izzet prowess style decks such as Lava Dart and Mutagenic Growth.
Perhaps Thrasta's natural home is not in what we would typically think of as a green blitz style deck, but more in a storm type of deck like the cost reduction ability. If we cast a few rituals, we can suddenly have a 7/7 hasty threat that our opponent might not be prepared for in sideboarded games.
"Trample over planeswalkers" is a fun new phrase that makes perfect sense. This dinosaur crashes over your opponent's little friend and continues on to smash into them. This makes gameplay much easier when don't have to decide between finishing off that Teferi, Time Raveler or hitting them for a huge chunk.
The final ability completes our reminder of Questing Beast – a green Legendary creature with a ton of text, haste, crushes planeswalkers, and is difficult to deal with in an unexpected way. The hexproof ability will ensure that Thrasta does in fact kill your opponent's planeswalker and/or gets in for one huge chunk of damage, not letting your opponent use their open mana for their removal spell.
Thrasta also pairs very well with the recently spoiled Aeve, Ooze Progenitor!