And to think they're bad enough even in a normal playthrough, what with unreliable revival methods... 5 on 1 WILL suck. No beating about the bush here.
Aside from wasting precious drops of the Water of Life, it's just Spark, isn't it? At least I wouldn't have to worry about revival here. Still though, it was extremely difficult
UPDATE!!!
Went back to Dehkan Plateau and utilized Pound to get through the shortcuts. Got a Nut which required Lash. Found Piers's ship. Walked past Indra Cavern because with Zagan undrafted, it'll only serve as ammunition for Valukar.
IronFelix - Level 6
Score - 6
Total Score - 26
I had Felix use Cannon to attack, Breath to heal, and summon Jupiter and Mars after that. It ran away at first but I fought it again and beat it.
I went to Madra to sell my extra items and to meet Piers. Then I crossed the bridge and got the Pirate's Sword. Entered Yampi Desert.
BlitzyFelix - Level 6
Score - 6
Total Score - 32
Took a few tries to bring it down. Felix unequipped the Mysterious Card and held both Echo and Iron. Used Echo, Iron, and Ramses, and healed with Cure when necessary. The second Ramses defeated the Djinn.
I reached the King Scorpion but the battle seemed quite difficult, so I decided to get more Djinn. I Retreated from Yampi Desert and went to Mikasalla and then tried to fight Sour. Apparently, Sour was also too difficult for me to beat, so I went and finished the entire Air's Rock and got Ether from Maha, before fighting Sour again
SourFelix - Level 6
Score - 6
Total Score - 38
Cannon did nice damage, as did Mars. But the main thing which saved me here was Procne.
I tried to fight the King Scorpion again... Theoretically, the battle should have been easy, because I can only get hit once per turn, and I can Cure when necessary since King Scorpion can't do more than 60 damage. Despite this, I was still crushed, because of poison and stun. For the poison, I went back to Madra and bought more Antidotes.
King ScorpionFelix - Level 6
Score - 6
Total Score - 44
As for the stun problem, well, this boss has quite a lot of HP, so I can't just keep trying different ways of rushing through without getting stunned. Kay gave me the idea of exploiting the scripted RNG to avoid status effects. So I wrote down exactly what I was doing, and if I died (only possible through status), I would redo everything but try something different on the turns where I get stunned/poisoned (to save myself) or hit by Desert Gasp/Sand Breath (to speed up the battle by healing less). Here's what I got:
I then made it to Alhafra. But I knew that Briggs is going to be really difficult, if not impossible, at my current state. So I went back to Mikasalla and got Spark and Megaera, since I have Scoop now. I was still scared of facing Briggs though, so I went all the way to Gondowan Cliffs, hoping to get as many Djinn as I can. There was a nice scene that I never saw before where Felix finds the Kibombo warriors planning for their raid. I couldn't go too far, because one of the ropes was missing, but I was still able to get the Laughing Fungus. I'll need that to get the Wheat Sword, right?

. Anyways, the main thing I came here for was
KindleFelix - Level 7
Score - 7
Total Score - 51
This was tough. Not only did I have to rely on Jenna and Sheba's Djinn for summons, but I also had to rely on Blitzy's stunning effect. Blitzy > Procne > Ramses > Mercury > Mercury and it fell while Felix had only 13 HP remaining. He also leveled up, even though this was his first battle after King Scorpion.
I used the Sanctum Trick to get back to Madra (which was the only reason why I stopped there on my way) and then went through Yampi Desert again to reach Alhafra.
BriggsFelix - Level 8
Score - 8
Total Score - 59
Even though this battle didn't take as many tries as King Scorpion, Manticore, Saturos, Kraken, etc, this was most definitely the most challenging battle I faced so far in this draft. Felix became a Trainer, chose a Djinn combination of Fog+Cannon+Breath for maximum durability (Spark offers 1 more Defense than Cannon, but no Attack boost), and ate two Apples and a Hard Nut. The result was that physical attacks did around 1-2 damage, and Echo Cut dealt 30 something damage.
The first half of the battle involved Megaera and Impact increasing Felix's Attack, and Orc as the main source of damage against the pirates. Orc 2HKO'd each pirate or 3HKO'd if they heal, but they seem to prefer healing Briggs over themselves. The hardest part was predicting their Oil Drops. That was the only real threat they carried, but each pirate only carried one. The pirates make sure they use their items, which might sound bad in the sense that I can't kill them before they Oil Drop, but it also means that they each waste one turn on a useless Smoke Bomb. All pirates outsped Felix, so I had to be careful in timing my Pixies. The pirates focus on healing Briggs, and Briggs likes saving his only Oil Drop for last. When there was one pirate remaining, I ran out of PP, so I summoned Ramses and used a few physical attacks.
The second half of the battle was a duel between Briggs and Felix. The pirates made sure Briggs was full health, and that Felix was drained of PP. This was even more intense. My healing resources were limited, and Briggs used Echo Cut every turn. Until now, I have never seen any Golden Sun boss ever spamming their signature move like that. I used a Nut to buy myself enough time to unleash Cannon > Breath > Megaera, for a nice Attack boost. Most of the time, I was just using two Herbs followed by a physical attack. Cannon slowly got stronger and stronger, thanks to Megaera, and it eventually killed him. This part of the battle alone costed me 10 Herbs and 2 Nuts.
btw the Tamer series should seriously rise in the Class Tier List. And Megaera, despite being weak, truly deserves its place at the top of the Summon Tier List.