Just on my way to bed, but I'm wondering if Cliffie is truly being aggressive or if these are "love bites" with a little too much force behind them. I get those from my cats all the time but they've also learned good bite inhibition from their siblings, so they rarely break skin (and they're still young - 6 months). Could be that Cliffie never learned how hard is too hard. I'd suggest being patient and persistent and hopefully he'll eventually learn to (I know, easier said than done when you're bleeding!).
"To close your eyes will not ease another's pain." ~ Chinese Proverb
“We must not refuse to see with our eyes what they must endure with their bodies.” ~ Gretchen Wyler