If you are using PrecApr, could you get into ET with something like Warlock4/Wizard1/ET? You only need 5 levels to satisfy the skills for ET, and Warlock 4 gets you a Lesser Invocation and at least 2d6 EB, IIRC.
Actually you need 6 levels of Warlock for a Lesser Invocation; however ET only requires Least Invocations which you get at Warlock 1.
You would need Warlock 3 for the 2d6 EB.