It's *1.5 to one damage type after it does a WS and *0.5 to all other damage types.
If it were *2 or *3 you would have 15-25k Ukko's when it was in slashing mode. Highest I've ever seen Ukko's on that particular mob is 12kish and this was from someone that averages 6-8k ukkos normally with spikes above 10k sometimes.
