Solar-Eclipse Arc

Solar-Eclipse Arc (そらえくりぷすあく) is one of the Lost Magics that allows one to use two other types of Lost Magic, that is: Solar Magic and Eclipse or Lunar Magic. This magic is also an ancient magic with its creation dating back to before even Dragon Slayer Magic and most Slayer Magic in general. The magic works by manipulating the caster's aura to turn it into an element of its own.

Description
Not much is known about the Solar-Eclipes Arc magic except for the information that Tsuna and Riku have chosen to share with others. It is said that a dragon created this magic during the era of god (10,000 years ago) and it is with this magic that he faught against god during the rebellion of ground zero that occured 10,000 years ago, although the outcome of the battle is unknown it is believe that Greydron- Solar-Eclipse Arc's create won. At least that's the story that Riku gave Tsuna.

Through the use of Solar magic the caster is able to condense his magic aura to the point it becomes hot enough to melt rock. He is then capable of using this super condensed aura as he pleases to either create massive blasts of energy, to propel him allowing him to fly or to create walls of defense.

The abilities of the Eclipse Magic are still a mystery as they have never been seen in action. Also as it would turn out Tsuna himself is incapable of using this magic. According to Riku, Tsuna's body is incapable of handling the darkness that is the Eclipse Magic.

To allow the caster to replenish his magic power this magic allows the caster to absorb magic from the earth. However, this takes such a long time to do it is highly unfavourable for use in battle.

Weaknesse(s)
The Solar-Ecipse Arc's greatest weakness is that it drains the caster's magic like water through an open tap, which leaves them very tried after only using it for a short while. This is because to use this magic one has to summon up a great deal of magic power, even for the simple spells, although that is also the reason for the magic's great power.

Due to the magic's nature overusing it tends to drive the user into a frenzy where he will attack and kill everything in site until his magic drains completely. To prevent this Riku put a seal on Tsuna such that if he were to use his magic past a certain limit the seal will drain his magic completely.