Could someone explain the retarded spanish numbering system to

Monarchies in general just have weird rules. Don't think about it too much.

It had something to do with monarchs taking numbering from both Spain and the evil tumor of Germany

>>3025448
Roman empire had tradition of Emperor's titles in which Ferdinand V means Ferdinand during 5th term of reign.

>>3025667
I thought Romans were Italians, not Spaniards

Some of those numbers are of order of succession of the HRE, not Spain.

Charles V is in reference to the HRE (he was the fifth emperor named charles), he had a different title as king of Spain. I think that might be the case for all the examples you posted

>>3025764
The last pretender to the Byzantine throne sold his claim to Isabella and Ferdinand

>>3025797
This. OP is a literal brainlet.

>>3025448
Carlos I of Spain, Charles V of Holy Roman Empire

Carlos II of Spain, Charles II of Spain

Habsburgs had more than one domain

>>3026236
How about Ferdinand V and II and Isabella I and III?

>>3026257
Oh wait, OP is just a dumbass.
Ferdinand V and II were the same person.
Isabella I's mom was also Isabella, so Isabella I's daughter is the third Isabella