The average rate for all of the dragons seems to be around 1:10-12k. Assuming the (conservative) 12k to be accurate, the odds of you not getting a visage in 13,537 kills is nearly 32%. The odds of going 13,537 kills or more dry after killing 100,000 dragons would be 99.789%. The odds of this type of dry streak are HUGE. You aren't even unlucky. The dry streak of which fewer than 5% of players would get is a 56,246 dry streak within 100,000 kills. Getting a visage within the first 1000 kills is less than 8%. Within the first 100 would be less than 1%. Sorry, good luck with that.