The idea of making Hardmodes like in Ulduar is a great idea. Continue this practice! But it seems to me that you are afraid of making bosses too difficult so as not to scare off the players. But that's the point. Players come and kill the boss, if they can kill him in difficult mode, fine, if not, then kill him in normal mode.
So the Hard Mode In the ES turned not be difficult. The players simply take the little dragon aside and hold it all in a group of 4-5 players. As a result, the boss remains ordinary.
And if you make a small dragon a "servant aura" that will not allow you to take it away from the main boss at a distance of more than 30-40 yards? And if he is taken further away, both bosses will fly into a rage. I wonder how much more difficult the fight will become? =)
Emerald Sanctum Hardmode
Re: Emerald Sanctum Hardmode
EC HC = AK40 (Hard mode should be harder!)
Raid Karazhan = BWL
Look at the level of items that drop from bosses (in easy or hard mode) to properly compare raids
Look at the list and order of raids in the Atlasloot