[Baalz]

Sounds like you've got the right idea in raiding him and heading for blade wind. You should also consider the more mundane counter early on - archers. As Pangea, centaur archers are a bit expensive, but if you can land a couple indie shortbow provinces you should be able to field several archers for each jaguar once you account for crappy Mictlan scales and holy recruitment limits. A hundred short bows will tear up some jaguar warriors as they're trying to make it through your meanads, even if they've got an astral bless. Another potential counter is minotaurs. Goldwise you come out ahead if each minotaur kills more than two jaguars before dying, a feat not at all hard to if you're clever enough to let the minotaurs get the first hit in. Once you get haste researched think of a squad of minotaurs as a missile - it'll tear straight through large formations causing great damage before expiring.

On the raiding front, remember not just to target his blood hunters but also to target his high income provinces. If he's blood hunting he's gonna be relatively short on gold, it can be surprisingly easy to cripple his economy as he's trying to ramp up to demons. A lot of people miss this, if he's not got gold he's either got to completely forgo recruiting troops (not feasible until late game) or "turn off" some blood hunters. Also, consider spells which raise unrest. Monster boar and rain of toads can be great compliments to a raiding strategy and greatly compound your economic advantage. They also can greatly hamper his bloodhunting as it's not practical to place domes over many of the blood hunting sites and unrest raisers make blood hunting almost impossible.