If you want to make a dreamdin use:
grief pb
eni
hl
loh
raven
rare stat ring
soe
gores
The reason why your damage doesn't increase much with lvl30 fire is because lvl 30 fire aura only gives you around +1.3k average damage before any -res or conviction
If you really want to make a dual dream, hoj, dragon din you have to adjust your ias by either use hoj pb (which gives you absolutely no damage), switch to fana (which isn't useful because you won't do much phys damage anyway) or use a1 faith merc which is also useless except for providing aura.
Nonetheless I do like to go for them from time to time as they are still quite fun to play and there is no possibility for any immune mob. Just remember that they are extremely squishy due to lack of high physdamage and almost no gear choice to select because of ias issues (so no dracs or much %ll for example)