You can probably handle it solo, regardless of your build, if you simply maximize your poise and DPS. Equip as much of Havels armor (or something similarly high in Poise) as you can without exceeding your equip limit, then two-hand your best DPS weapon (buff it with an item or spell if it's buffable), and keep the Grass Crest Shield on your back for faster Stamina regen.
Face rush each the King and spam attacks into him while simply tanking all his attacks. Don't bother blocking with your shield. Only dodge his grab attack if you can since it's a time waster. Bring a full 20 Estus into the fight and heal as needed while tanking. Remember to take an extra few swings during the King's dying animation since damage continues to register, then rush the next King and repeat.
The GameCube features two memory card ports for saving game data. Nintendo released three official memory card options: Memory Card 59 in gray (4 MiB), Memory Card 251 in black (16 MiB), and Memory Card 1019 in white (64 MiB). A few games were known to have compatibility issues with the Memory Card 1019, and at least two games have save issues with any size. Memory cards with larger capacities were released by third-party manufacturers.
The Memory Card numbers indicated the number of save blocks available on the card, and each number is 5 subtracted from some power of 2. This suggests that 5 save blocks are devoted to some sort of system information. Simple math can be used to find out that each save block is a 64 KiB page of data. (For example, (59+5)*x = 4 MiB, x = (4 MiB)/64, x = 64 KiB)
Some very good games have already been mentioned. Here are a few more to consider:
Wizardry 8 - create a party of 8; first-person turn-based combat; focuses on dungeon crawling and world exploration
The Temple of Elemental Evil - create a party of 6; isometric turn-based combat; uses D&D 3.5 rules; primarily dungeon crawling with optional quests in town
Pillars of Eternity - create a party of 6; isometric realtime-with-pause combat; plenty of dungeon crawling, but maybe too much story
Baldur's Gate: Enhanced Edition - create a party of 6 (in solo multiplayer game); isometric realtime-with-pause combat; uses D&D 2.0 rules; open-world exploration/combat with simple story and sidequests
Totally worth it. I'd say it's easily good enough to justify its full price of $40. I bought the game for $20 during the summer sale, as I'm not much of a puzzle guy despite loving the Portal games, and after finishing the game I felt bad for getting such a solid game for so cheap, so I bought the soundtrack and the Gehenna DLC.
As far as puzzle games go, Talos Principle is broadly similar to Portal. Both have first-person spatial logic puzzles, careful attention to detail and environmental storytelling, strong atmosphere and sense of place, and (if you use the Serious Sam DLC) a fun sense of humor.
Talos also has more lore, tons of secrets to find, and some seriously devious optional challenge puzzles. On top of all that, it manages to explore some thought-provoking philosophical ideas in a way that's approachable and genuine without becoming pretentious or preachy. Oh, and the soundtrack is fantastic, too.