Title? I don't need no stinkin' title.
We got to pre-buff a bit. Our sorcerer has an item which allowed him to bless the entire party, and the paladin cast aid, and my fighter (who has chef) gave out a few measly temp hp. The sorcerer won initiative, fireball, hit all of them... does nothing.
The 3 young remoraz has AC 16, the big one AC 18 (not 19, sorry about that). The big one also attacked twice a round. The 3 young one rushed forward due to high initiative, while the big one was last.
The returning player (also level 7) is a Paladin of Glory with a giant slayer 2nd handed sword - you'll note that's not super helpful vs remoraz. He also has a wand with ice powers, and he wasted some time learning it does nothing vs remoraz. He rushed forward to distract the big one and keep it busy.
Particularly painful was when he took a huge hit to protect his horse, and then "cleverly" used the ice wand to create a sleet storm to cover his retreat and slow the remoraz down... but it has tremor sense, so the GM ruled it didn't have disadvantage on the AoO, hit the paladin again, brought him to zero and swallowed him.
We had 2 allies - two awakened trees - but they did not act for 2 rounds, as we learned that they apparently don't help you unless specifically told. They then delayed the big Remoraz for 2 rounds which was clutch, but also very importantly the GM ruled that they punched the big remoraz in the stomach hard enough to make it throw up, thus expulsing the paladin from its stomach. This was the GM going easy on us, because this situation was going to be a guaranteed PC kill otherwise (stomach acid damage = auto failed death saves...). The sorcerer was able weave through the commotion and heal the paladin, which then used lay on hand to get back to near full.
Our monk almost got killed and he resorted to hit and run tactics. Using a +1 whip, con 12... it was rough. I think he managed to land 2 stunning strikes the entire battle.
My fighter was ... fairly effective. Not a ton of damage, but lots of defensive use of his psi power to shield the others and the luck feat to keep himself alive. I know some of you want to know what items he has and the ones that mattered in this fight was +1 studded leather armor and a sun blade - yes, it's a good weapon, but in this situation, it's a + 2 sword.
We managed to kill the 3 small ones, but the big one was still kicking and a lot of our resources were depleted - the paladin was back down to 15 hp. But then more allies showed up and we won the fight. But yes, it was brutal. Without the bless OR the trees we would probably have lost people. In fact, you could say we did because the GM essentially gave the paladin a get out of jail card, because there was no way we could have rescued him.
So in other words, the DM may not have used their infinite dragons but instead used infinite remorhaz. Which has been my point. The DM can always make more difficult encounters. Ultimately it's up to the DM to figure out how to make encounters fun. Did they really plan on exactly when reinforcements would arrive, or did they just wait until it was dramatic?
D&D is as challenging as the DM and players want it to be and no encounter calculation can take into account every variable. In this case the paladin made some, shall we say, less than tactically sound decisions. The DM made some calls that were not strictly in the rules (it takes 2 turns to swallow someone, attack and grapple first round then swallow second), the punch getting the paladin out.
But imagine if the sorcerer had gotten off two lightning bolts managing to line things up just right while the targets failed their saves? What if the paladin hadn't taken unnecessary hits or done ineffective attacks? Would this encounter suddenly have been "surprisingly easy"?