Watching Aizen lift himself into the air avoiding the river, Trunks knows he has to act fast before Aizen goes on the offensive. He channels his doton chakra while keeping a close eye out for Aizen. As soon as he sees him change direction, Trunks forms the Ram hand seal to cause the earth, in the spot that Aizen is set to land, to loosen and begin to turn in on itself. Spinning around like an earthen whirlpool, Trunks watches as Aizen launches himself into the antillion.
I feel like I should explain this part, so hang with me. The move you used to go into the air is a D-Rank, and therefor not very powerful. I'm willing to accept that it is enough to get you out of the way of the mud river, but you shouldn't go very high after that. Next, you used an air travel technique that takes you to mid range usually. This tells me two things: One, your head should be turned away from where you will be landing, limiting your sight of the technique. Two, given you aren't very high off the ground, and the technique has enough power to get you to mid range, you have to be moving fast. In fact, I would argue that you would be going fast enough that changing your direction again while in the air should be nearly impossible. But hey, all fights are open for debate, right?
Trunks concentrates his katon chakra into his chest, and looks at Aizen with a look of absolute fury in his eyes.
Your arrogance angers me Aizen. You may have played a part in making me stronger, but that isn't why I am strong! I'm strong because I have to be! I'm strong because there are people that I need to protect! I'm strong because the people of Amegakure need me to be! I'm strong because someone has to eliminate evil from this world, and right now, Aizen, that evil is you!
As he finishes these words, he releases a very fast burst of flame, aimed for the antillion technique. Once it lands, a flame pillar will erupt from the antillion technique, causing major burns to anyone caught in it. Also, due to the loose nature of the earth, it would cause the antillion to become a vortex of spinning lava, that would further trap Aizen, ensuring his defeat.