is not 50-50.

Once you hit 1000 you unlock both of them and you can pull both of them as a common rares.

If you are lucky (so if you never get early rare pulls and if you get dupes only after you gained ALL the common rares) you get Madara at 1050 and Naruto at 1120 or viceversa.

The point is that if you got ALL the other rares before the 1000th pull, then your first pull that isn't an early lucky pull is one of them and the second pull that isn't an early lucky pull is the other one.

It's almost sure that you get both of them before your 1300th draw (unless you are the unluckiest person in the world).

P.S.: for early lucky pull i mean that you get a rare out of a random rng roll at your 1st-69th draw after the previous rare, not a rare that you get because you hit the counter of 70 (if is really 70 in that treasure).