The Molten Hellions' theme appears to be the shared searing hot surfaces of both worlds, which attract many Fire Meteos. The Molten Hellions serve as one of the two second groupings of Star Trip, being accessed whether or not the mission of the H20 Planetaries has been accomplished. The mission of this grouping is "Launch 100 Meteos or more!" which will let the player go to the Mechatropoloids if the mission is completed successfully, while if the players chooses to after winning or fails the mission, the Stray Planet will be accessible.
This mission is much easier than the upper path one. Not only do you only need to launch off 100 meteos (which you probably do without trying everytime you play Meteos), the planet Firim is in this group, and it is the planet where you play the 100-meteo war for a reason. Actually, this mission is so easy you don't even need to read any of this. Maybe you could even say this mission is easier than the mission of H20 Planetaries.
As Firim Edit
Even though Firim only has 7 columns, it is actually the best planet for this, even though Hotted works very well too. Why do you think you can win 100-meteo war in less than 10 seconds? Play like you normally would. There's no need to slow down so the other planets don't die first, you will get the 100 meteos before that happens.
As Hotted Edit
Hotted is also a very good planet for this. Hotted is a little bit harder to work with because you won't be doing screen clears easily, but you can just send Meteos stack per stack, since Hotted has a bigger grid to work with than Firim, and you will still hit 100 meteos safely.
Molten Hellions | Chlorophylls
Stray Planet | Mechatropoloids | Earth Lovers
Bubblies | Dimensionals
Electric Nymphs | Hot & Chillies | Clean Air Club
Twin Moons | Illusionists | Rare Cultures
Meteo | Hevendor Realm