I am not familiar with c9's map pool. I dont think they have a perma ban and SEN is only good on 3 maps from what is shown so far : Pearl, Haven and Split. I really think c9 have a solid chance
From what I can tell they're both good on the same maps being lotus pearl haven and ascent but also SEN played them against far worse competition generally and I do think C9 is better than them on lotus and Pearl so it depends on the other 2 maps
Some of c9 good maps like split and haven are Sens best map as well
C9 icebox is okay as well as Sen
Lotus tho will be a but of a problem on sens part considering c9 are pretty good while sen isnt
the thing about this match is even if sen win, people are gonna downplay it by saying "oh sen isnt good but c9 just chokes" blah blah blah, all the basic ass shit they say so it wont even expose them.
but wtv we'll see