Professor Gai is an instructor and part of Master Togo's staff, providing training to monastery students. He has a very grand mental lexicon and is very sure of himself.
"At long last, the thriving mind I have awaited has arrived. Most comprehend mortality only to a minuscule degree. You, however, will soon perceive the ecstasy of oblivion, for you will be a great Ritualist one day! I expect considerable achievements from you, but not to worry: all who choose the path of the Ritualist are already on the road to eminence.
What would you like to learn about?"
In Sunqua Vale, if your character is not a Ritualist:
"Most comprehend mortality only to a minuscule degree. You, for example, will never truly perceive the ecstasy of oblivion, for you are not a Ritualist. Should you wish to evolve, it is conceivable that I could be of assistance. For now, however, you should seek out your headmaster."
In Sunqua Vale, if your character is not of Factions (the only other instructors which make a campaign distinction are Sister Tai and Talon Silverwing):
"I am afraid I cannot help you. You are not a student here. And do not bother trying to become one... the honor is reserved for Canthans."
Gai sometimes uses Shelter outside of combat when idle. Thus, he will often not be able to cast his spirit during a battle because of the long recharge.
Tips
It is important to note that despite being labeled a spirit henchman, Gai only uses 2 spirits. He is primarily a healer, not a spirit user.
He tends to be an excellent support character, (usually) resurrecting party members quickly in the middle of a fight, so when you have Healer or Protection Henchmen, they do not waste time doing so.
"One would think that the best way to withstand this plague would be to confabulate with the spirit realm. However, I am dismayed to find that Master Togo has not yet consulted me. I am of course the preeminent authority on the spirit realm and those ethereal denizens who reside therein. Did you have a question for me?"
"The accumulation of living within the city makes it a ripe location for the contagious development of the plague. If we keep our wits about us, perhaps we will subsist long enough to see this jaunt to the mainland be successful despite the odds of being principally stacked against us.
"I have heard anecdotes of the Kurzicks' skill with speech and theory. It is truly magnificent to correspond with people of my own intellectual caliber.