I think any marine in that close a proximity with a large tyranid beast would just empty the mag into the things head.
None of this one shot stuff.
And thats a flesh wound to a marine.
Nice work, but that pose of the lictor is a hard thing to do anything with, let alone try and work it into a diorama.
Despite his injuries, I´l put my money for the space marine. Those who think otherwise, should consider how large bullets Bolt pistols fire......And the fact that they fire mass-reactive bolts too, wch explode from impact. Id say that if the marine gets a clear shor for the head lictor is pretty much dead........ oh and the diorama is nice too