As of now, this card is the first alternative win condition the devs have published into the game. There are a lot of ways to gain favor in the game by killing minions, hitting the opponent's god, and cards with favor manipulation effects with players gaining more as the rounds go on with a cap at 3 favor per hit/kill.
Archetypes that can take advantage of the card
- Hyper Control War
Control Cards
Your typical aggro player's worst nightmare, War has tons of tools with board clear after board clear unless you are also facing a mirror control matchup you can just watch your favor shot up while watching your opponent being slowly cooked in despair.
- Favor Ramp War
Favor Cards
A neat little archetype if you want to go all in the favor theme. There are a lot of favor manipulation effects that have been printed cards like Hydna can help manage the board somewhat and 1 offs like Blessing of War too considerably increase your favor in one go.
My Opinions on The Card
Hopefully, we will get more ways to get favor with other upsides in stats or even a second effect. Honestly, I also hope that the card itself will be buffed I mean 100 favor is so much the largest amount that I have obtained was around 40~ even with a control deck.
You are already at a disadvantage at the start of the game as you have to sparingly use the Sanctum. It may not seem as quite a big deal since you are a control/combo deck but the Sanctum can also be used to buy cards to deprive the opponent of outs as well.
I consider the card as a gimmick for now as most games don't even go past the 8 mana curve which makes it all the harder to gain favor the upside is that most aggro decks will probably just concede after you clear their boards a 3rd time which other control decks can do better. While the favor deck has to compete with an abundance of fast-paced decks in the meta and has to run more board clears to get by.