A little bit about the paint job. This piece was heavily inspired by the artwork and lore in the Thramas book. Every world burns, every inch of ground a phosphex soaked hell.
The Lion in black and red has more of a dangerous colour combination. Here he is the destroyer of worlds, not the crusader. He is the knight of old Caliban seeking monsters to slay.
The base might not fit with your army – and I agree, it wouldn’t as a display. However, he detaches and the only OSL is on the brazier. He will be able to fit alongside your force no problem. And I imagine that phosphex follows the Lion like cherubs tail Sanguinius.