Although Victini has been called a Sun God, it is better understood as a backup power supply. Victini is a living fusion reactor, capable of controlling the pace of its fusion; should the Sun ever be extinguished, it possesses sufficient energy to warm and light the earth for long enough to allow Arceus to build a new sun or tow into position another star. Yet to give any creature such immense energy is to endow it with unique, unparalleled attacks and remarkable ability in combat, and for this reason Victini is also called the god of victory.
Prayer to this god of victory, however, has failed to make anyone invincible, for Victini never smiles on an individual permanently, but capriciously shifts its favor time and time again. No matter how hard one trains their pokemon, no trainer can ever ensure themselves a championship, only improve their odds, and for many the frustrations of defeat gave rise to greed. Victini's fusion energy has seen it become as much a target as a god; pokemon trainers have struggled sought time and time again to capture this creature, for Victini is said to guarantee victory in every match.
Victini has gone into hiding on an isolated island, not out of fear of being captured, but because it had grown bored of being constantly challenged. Trainers, blinded by the prospect of becoming invincible, have unfailingly overlooked the corollary to Victini's guarantee of victory; it can never be truly captured, for to capture a pokemon is to defeat it! Only those who sought to use Victini's power to protect the world, not to rule it or use it as a source of personal greatness, have ever held this creature within a pokeball; in these rare instances, Victini was captured only because it threw the match.