Temporal Summon is a new summon introduced in Yu-Gi-Oh! Starlight Force along Starlight Summon. This summon can be activated if you have any number of monsters with a certain level depending on the monsters required to summon the monster.
In order to summon this way; first, pick a Temporal Monster in your hand with a certain level (ex: Constellation Pegasus/Level 8); second, if that monster requires two monsters (which it does) you must have 2 level 4 monsters on the field; third, banish those monsters.
Some monsters require one monster, if they do then they require a monster with the same level as the Temporal Monster. Monsters that require more than one have monster with half of the monster's level. Odd numbered levels always require one monster. Monsters that require one monster are usually weaker.