Knightfall
World of Kulan DM
Man, my brain is completely letting me down. I forgot about down speed while flying. Maur and Quinn's speed is double while descending. Up speed is half.You can have Maur take the potion from Quinn as a free action. If you have to choose him to drink it this round and then move,Maur won't be able to reach Tarrak this round, as the ghast lord has finished feather falling as is now more than 60 feet away from Maur.
Even if you have Maur hold off on drinking the potion, he won't be able to reach and attack Tarrak this round. He cannot charge, as he has to fly past the edge of the crevasse before descending towards the ghast lord.
After Tarrak landed, the ghast lord took another inflict vial from its belt and drank it.
Anyway, it's your turn.
Sorry about the mistake @Neurotic.
So, you don't have to cannonball Tarrak to reach him and attack this round, as long as you don't drink the potion first. You can still choose to do so, if you want to drink the potion first and then stop flying, land, and jump over the edge.