If not yet so, could ceremony be stackable? Meaning that if you use ceremony
for 10 times in a row, a success of a spell would increase significantly,
compared to a one succesfull ceremony. In the old days ceremony took 1 ep
only when it succeeded, which was very nice, but now there is no way of
knowing whether you got it right or not.
Or atleast if you use ceremony for 5 times, the concurrent ceremony would
not 'clear' the previous. This way if you'd know quite surely that your
spell has a good chance of succeeding if you do ceremony 5 times a row.

If it is that way already, then consider the small stacking.
If that is also implemented, then I'll just go and shit in my hat.