Do some champs cost more ISO?
I've been playing this game for over 3 yrs and only saw this with unstoppable colossus I think.
Normally, with a 4*, you throw in 2 t5 chunks of ISO and you're at 10/10. I remember uc costed more, but that was long ago.
Now I just got sentinel and as always I want to take him to 10/10, throw in 2 t5 ISO and...
... 8/10. Wth? What am i missing here?