Its a 10% chance to get a 0.1% % increase per mission run. Difficulty or length of mission has no effect upon the odds of getting the increase as far as we know.
So, does this mean that I just need to spam Earth Shrine over and over, until Tm is unlocked??
Also, how many Hero Rings are a good number? 10 (2 to each of your heroes?)?
 
	 
				 . Going to make atleast 4 more, maybe 6 with time.
. Going to make atleast 4 more, maybe 6 with time.
 
		 
 
		 
 
		