The ultimate synergy Vengeance has is with Vantage. Vengeance requires low health to get the most, and Vantage makes sure you get your painful hit in. Unbeatable when you're using Nosferatu/Aversa's Night (especially when forged). Wrath isn't as necessary. Or at least I haven't needed to use it. Limit Breaker and Armsthrift take massive precedence.