I would like to see Boss 5 from the Old School raid be implemented into Reborn. He could be a final boss in a dungeon or even maaaybeee a world boss. Could bring back Boss 4 as well and make a 10 person dungeon fighting Boss 4 then Boss 5. Would be pretty epic if you ask me and those two bosses really required everyone to be on their feet and were very interactive and I just loved them both. Dealing with the bells and two bosses at once, then Boss 5 taking people to “Hell” since you brought back spiro might as well revamp the old raid gears and use them as drops.
Second thing I would like to see brought back is the triple boss from desert crypt. Loved being decurse mage and having to time the kill just right. I liked the old dragon boss but I wish it had a point(s) where it would fly up and around where we can still damage it but we have to hit it first obviously, in those points little dragons could come at us all three types and all sorts of colors or even all the same color would still be awesome.