What was Sega thinking? First you have to wait for rain, with periods where it can go without raining at all for 30+ minutes.
Next it needs to turn into a storm which is also purely random chance.
GIGANTIX HAS SPAWNED.
Oh but wait, anyone not lvl 20 effectively can't harm it and is actively detrimental to fighting it due to how scaling works for them.
Oh also they despawn whenever the storm ends, with them lasting for up to 5 minutes or as short as 2!
In order to fight them, you basically need to grab a group of people to ensure you're the largest mass of players when a storm does occur (their spawning mechanics have them spawn near the largest group of players in the zone), hope nobody undergeared/underleveled is nearby and hope you can kill it before the invisible timer decides you took too long. The other catch is that due to them being lvl 24, and just having higher stats overall, your damage will drop significantly, so you need to bring your absolute best to have any kind of a chance at this awful encounter (oh also the gigantix boss does enough damage to 1-2 shot anyone).
So you have a world boss you need an organized group to fight, and possibly idle in a zone for 30+ minutes before getting even one gigantix to spawn, which may despawn within 2 minutes of spawning, while having jacked up health and defences higher than any dread/veteran enemies you find in exploration fields.
I've been sitting in one zone with 31 other people for close to 2 hours now and have had one rainstorm out of 4 rainy periods, with said rainstorm only lasting for roughly 2 minutes. What the hell Sega?