Assume, that due to fortunate (from Christian's POV) chain of events Christian's wife Isabella of Austria became heiress of Habsburg Empire (so her brother Ferdinand fell ill and dies after arriving in Germany, her older sister Eleanor dies in childbirth and Charles V has horse ridding accident in 1520. Isabella is thus oldest surviving daughter of Philip Habsburg and Joanna the Mad. What happens? Christian is already King of Denmark, Norway and Sweden at that point, Burgundian Inheritance should be easiest to secure for him (still not easy-France would use opportunity to grab at least part of it). What about the rest? In Castile his mother-in-law Joanna the Mad is still rulling Queen in theory, meanwhile Aragon preffers male heirs-and closest male relative of Charles V is Christian's son Hans. There is also Imperial throne and Austria left vacant. But considering Christian's troubles in Scandinavia I doubt he'd be able to get all of these. Spain could be simply claimed by House of Aviz and participating in Imperial Election means neccessity of paying massive bribes. So, in the end, how much of his wife's inheritance he'd be able to keep? And is he still deposed by uncle? That seems even more likely than IOTL, considering numbers of new fronts he'd open.