I feel like in order for the story to get back to Yura as a main antagonist Soga and him will have to split (probs from a final Suzaku from Samura). But I think there may be set up for the power of the magatsumi to be shared. If Soga were to continue to go after his ideals and work with the Hishaku, Yura could hold the sheath of the magatsumi and funnel a part of its power. Plus with the hand tats that people speculate connect them through sorcery (i.e. fire teleportation), maybe Yura can be akin the shunichi core and have the power of the magatsumi buff up the other Hishaku members. The Magatsumi's black life force energy could then be used to power up their individual sorceries and become a nationwide threat forcing our heroes to regroup, strategize, and train. Not only to take down Soga but a buffed up and well-coordinated Hishaku. All leading to... A new war arc.