Hey I just wanted to clarify if the thunderous bludgeon is only STR 10 against enemies in the rear arc, or if the +1 to hit is the bonus from attacking something in the rear arc. Thanks.
The beastieboy's S10 attack is always one of its attacks, similar to the arachnorok's venom surge but without the awesomeness of poison and multiple wounds. The bonus +1 to hit does indeed occur when it is attacked from the rear.
Sadly, he pairs that S10 attack with only 2 other S4 attacks, and S4 thunderstomp. Which means, he's likely to lose. LD is bad, and he's not stubborn. He's cheap, but he may be too situational to make work.
Don't forget that the Bastilidon does not have any flanks. I'll be running mine next to my Temple Guard on their exposed flank. Both units will be charging the same targets. The Bastilidon will keep a flank charge from getting any CR bonuses and the TG should mete out enough wounds to keep the Bastilidon from breaking from combat. Also, the Solar Engine will have the TG hitting at Init 3.. with a little help from the magic phase, these guys could be hitting first in combat! (On their other flank will be my Ancient Stegadon with the engine of the Gods, finishing off my trifecta of Terror.. if I lose combat after that triple-threat charge... well, I probably lost in the deployment phase.) I'll see how well this works out on Tuesday.