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Okay, Your King has the DOS and is in combat with a ranked up unit. The Tomb Kings FAQ says that when the king is smitted he may use his special attack. Does this mean that in the magic phase, every enemy in base to base will take 2 automatic hits, just one hit or will just one model take 2 hits?
I hope it is the first one, making the destroyer simply awesome!
He is allowed to make 1 attack. This one attack may be the special attack. The special attack does 2 auto hits on every model in base to base.
Simply, yea, if the spell goes off the Destroyer is quite awesome.
As Deceiver stated, he can indeed use his smiting attack to get 2 auto S7 hits with Killing Blow on his targets. That is one of the reason that a TK with the DoE can be such an amazing character killer. 2 auto hits in the magic phase, and 2 auto hits in the combat phase.