An easy way to get HP is to create a knight and train him to level 40 with a high Fire mastery. Increase Fire mastery by getting special items such as Rune items. Hold at least 48 Fire Mana. Capture a Fire Elemental and research the spell "Fire Siphon". The spell Chivalry is also required which can be learned at level 40. Start a battle and check the resistance of your enemy. It is best if their resistance is 0%. First, cast Chivalry. It will remove effects like Poison and will raise your and your enemy's Mana to the maximum. In your next turn cast Fire Siphon. This will drain your enemy's Red Mana and add it to your life points.