In the 1.0.6 version (the only version i've tried it on) if you attack the enderdragon with Thunderbolt, it gives you the following message: "A fatal error has occurred, this connection is terminated." There's no crash report, only tried it in singleplayer. Nothing tragic, but i figured it was worth noting, the easiest fix would be to not use thunderbolt against it.

Game would crash when the target of ThunderBolt is Boss like Ender Dragon, etc.

This still happens.
See #772 and #774 (LambdaLib2 0.1.8, Academycraft 1.1.1, Minecraft 1.12.2, Forge 14.23.5.2815)

Since the issue is out-of-date I'll close it. Please file a new issue if you experience it again in the upcoming 1.1 version.