[Trumanator]

Leech has a pretty short range, which makes it hard to use on raiders which generally sit at the back while they buff. I don't know what priority it has with the spellcasting AI, but you could try telling your hunters to holdx5, cast spells and hope they cast it. Unfortunately this is an issue with most blood spells. Hellbind Heart and Blood Burst have slightly more range, so they might help. You could also try and use a sabbath communion to spam Life for a Life. That's a bit tough for B1s though, since you can't use extra slaves to boost your power for it.