Well.. I was able to defeat both the Dragonoid and Triple Dragon Challenge using Evolved DragonLord without too many difficulties, just really time consuming as it really is a war of attrition. You don't need even need Dragonlord's Patience or Rage, regular DragonLord should suffice. A trinket with an evasion/blind skill may prove useful though.
"Not so tiny bubbles" is an incredible trinket to consider getting. It has a no cost blind skill that has a very fast cooldown.
Here is my strategy for both bosses:
Phase 1: Take out the 2 spawns first, without overclocking the main boss. Once that is done, spend as many "stall turns" as you need to get yourself back to full using regeneration skills (HP and MP heal). You can blindlock the enemy if it's a simple 1v1 (since Dragonlord on its own should have 3 evasive skills (blind, shield, stone - combine with a trinket, you have 4), so this should not be too hard. Get the Dragonoid close to above 50% HP. Make sure you have all your high damage output skills and shield+stone skills charged up before reaching this point.
Phase 2: You should now have close to full HP. Raise up a shield before you take the Dragonoid below half health. This will give you at least 2 turns (3 turns technically, but you need 1 turn to take the dragonoid to below 50%) of "invincibility" before you start taking damage from all 3 enemies. Using those 2 turns, whittle one of the spawns to low health without killing it. Then use Stone to grant you 4 more turns of reduced damage. In 3 turns, you must then whittle the other creature to a similarly low health. On the last turn, multi and kill both spawns. You will have taken some heavy hits in between, but they should not be enough to kill you. You should be at pretty low health by this point, but it is now a simple 1v1 now. The rest is easy.
This challenge is quite a step up from the previous. Firstly, all enemies have basically equal amounts of health. It is important to identify which enemies to take down first, and in what order, as they each have special abilities. My proposed order is Gelunguis -> Trigoras -> Oratath.
The logic being:
1. You can't hurt Oratath quickly enough to overcome its heal ability, whilst fending off 2 other dragons at the same time.
2. Trigoras has a rage mode which activates when you get him to low health. You don't want to deal with that with 2 other dragons trying to eat you alive.
3. Gelunguis is the most powerful. It has the highest damage output, highest chance to stun you (which easily ends a run), but it doesn't have any "special ability" when you knock it to low health. This makes it the ideal one to go for first.
By the logic of the first point, Trigoras should follow next, then Oratath becomes a simple 1v1.
There are a total of 5 defensive skills that you should cycle through constantly
1. Trinket Skill
2. Shield (Darkness Dragon Spirit)
3. Stone (Earth Dragon Spirit)
4. Blind (Light Dragon Spirit)
5. Heal (Wind Dragon Spirit)
Ignore Oratath for the most part. He has the lowest damage output on average and all he really does is shield himself. Occasionally he blinds you, but it's nothing major. Instead, focus on keeping Gelunguis blinded at all times, or keeping yourself protected, may it either be shield or stone skills. You don't want Gelunguis to have a chance to stun you with its frost breath, or hit you with its damaging multi hit skills, so make sure it never lands a hit. Also keep Trigoras at bay with defensive skills - especially when he gets a 100% power boost. Shield/Stone is especially useful since it protects you from universal damage - combine this with Heal and you can get a significant portion of your health back. While cycling through these defensive skills, be sure to hit Gelunguis whenever you can with Offensive skills. You can't last forever, so taking Gelunguis out as quickly as possible would be ideal. Keep your MP at stable levels. Whenever your health drops low, take a swig of potion, and carry on fighting. It will take many many turns, but you can and will whittle down Gelunguis HP eventually. Repeat until Gelunguis is dead.
At this point, the worst case scenario is that you have low health and no potions. But it doesn't matter. Because of Dragonlord's defensive nature, you have more than enough skills to heal yourself back to full if you just focus on defense (don't even think about attacking Trigoras yet). Once you get yourself back to a stable state, the rest of the battle becomes fairly easy. Repeat Phase 1, but now Trigoras takes the role of Gelnguis, and Oratath the role of Trigoars. Beware that Trigoras can still deal massive damage so make sure you always have defensive skills on the ready. You should be able to heal faster than they are doing damage though. Repeat until Trigoras is defeated.
Then the battle becomes a simple 1v1 with Oratath, which should pose absolutely no problems at all.
Hope this guide helped a little to those who were struggling a bit?