Well the request is to make health more complex by only being able to gain health through sleep (or rest) but it will take longer if you aren't wellfed , and if there isnt an herb that does this already then they need an herb that you can use before you rest to speed up the health regen process . This process will replace any plans to have potions regain health , I don't think it's a good idea to have potions regen health (as I heard this was planned) because it favors combat healing and it would become a meta game! The blood system would work like it does now , but take longer to achieve a full heal and it would add in the variables of food, rest and herbs simply to favor realism but this simple change will make pvp , regular life , and living with wounds MUCH MORE COMPLEX, and immersive adding another layer to pvp and life itself.