There are easy and hard bosses.
For boss level 20-60 there are only easy bosses with power = level * 10,000 - 100,000

Easy bosses with level 60-99, Have power = level * 10,000 - 100,000
Hard bosses with level 60-99, Have power = level * 10,000 + 900,000

Easy bosses with level over 100, Have power = level * 10,000 - 100,000
Hard bosses with level over 100, Have power = level * 10,000 + 7,700,000

The level of the bosses you summon are alwasy between half your boss kill Count and your boss kill Count.

So a level 100 boss can have eigher have 900,000 power or 8,700,000 power.
and a level 60 boss can have eigher have 500,000 power or 1,500,000 power.
I seem to get the hard bosses type atleast 95% of the times atm.
I would like to see chance of hard boss not going over 50%.

So a player with kill Count 200 summon bosses with level 100 to 200, but as bosses 100+ have 95%+ chance of beeing hard so al least 95% of the bosses he summens will have of power 8,7 M or more.