The more you grow H&A, the more counters you get to stack on other creatures each combat, so you can make two or more sizeable threats at the same time
Our speed is about the same, but our threats are bigger
It gave new players a way to get into the game, offered a constructed format for players to graduate into playing largely with cards theyd gotten through drafting, if they were regular drafters, and gave new cards and new mechanics room to shine in a constructed format
The only issue is that it's locked into Abzan colors, so you can't play it in a 1- or 2-color deck
Yet theres also cards which go above the official number of 204 cards in the set
This can draw you a truly obscene amount of cards, and between extra turn spells and extra combat spells (being in both the correct colors) you could dig yourself to another wincon fairly readily