Charm/Possess seems solid, of about average power level for a spell. It seems stronger than Meditation or Restoration, and weaker than Fireball or Snowstorm.
Offering is good, potentially giving a hero 4 crystals for one red mana. But the hero probably won't be able to do much else during that turn. Sacrifice requires at least 4 mana to get it started, or 6 if you want it do something big. A hero would probably need to play Offering during the day to be able to afford Sacrifice at night. Overall, I would rate this spell as average.
Soul Harvester is above average for an artifact, providing Attack 3 plus a crystal. Occasionally you will be able to get more than one crystal from the basic effect, but usually not. I would probably take this over any of the mana rings. It certainly seems better than Sword of Justice.
With Horn of Wrath being reduced to Siege Attack 5, I would probably take Circlet of Proficiency over the Horn. The circlet's advanced effect is outstanding. There are usually some really good skills out there . . .
Offering is good, potentially giving a hero 4 crystals for one red mana. But the hero probably won't be able to do much else during that turn. Sacrifice requires at least 4 mana to get it started, or 6 if you want it do something big. A hero would probably need to play Offering during the day to be able to afford Sacrifice at night. Overall, I would rate this spell as average.
Soul Harvester is above average for an artifact, providing Attack 3 plus a crystal. Occasionally you will be able to get more than one crystal from the basic effect, but usually not. I would probably take this over any of the mana rings. It certainly seems better than Sword of Justice.
With Horn of Wrath being reduced to Siege Attack 5, I would probably take Circlet of Proficiency over the Horn. The circlet's advanced effect is outstanding. There are usually some really good skills out there . . .