In the world of Terra Nova, there were two types of mage spells that could be cast.
First were spells that could be cast individually by single players, where the spells they cast took up a spot inside their skill panel. And the second were group spells that needed a certain number of mages collaborating together to be cast.
These group spells did not take up any skill-slot inside the mages individual stat panels, and often did not require every single mage in the group to chant the exact incantation for the spell either.
Most of the low-leveled group spells only used the bodies of the mages casting them as a power source to fuel the main spell, while the caster was usually only a single mage.
And the spell that Leo faced today, was one such group spell, called [Rainbow Shot].