Undertaker has Rebellion hidden within his cloak.
As his opponent starts by blabbering, then forming a few handseals to initiate a technique, Undertaker starts by staying perfectly still, becoming one with nature and gathers natural energy, soon after he finds clouds beginning to form in the sky, seeing his opponent as an easy target, Undertaker goes for the offensive, using Aluminum chakra to cause several large pillars of Aluminum to rise out of the ground to attack and bind his opponent. Aluminum pillars rise out of the ground from beneath his opponent wrapping around his legs with versatility rivaling that of the wood element, while pillars of aluminum rise at the same time in front, behind and around him in order to pierce through his body from multiple directions. Each pillar of Aluminum is 3 meters tall and 1 meter wide. This can be done simultaneously while gathering natural energy as it requires no handseals, and obviously would happen fast enough to interrupt the rest of your move.
Cute, leaving yourself wide open for an attack, you haven't learned anything Asch.
Afterwards, Undertaker simply activates a skill that grants him to use a liquid variant of the aluminum metal if he so wishes, this activation is pretty instant and doesn't require handseals as well.
If you have time to talk, better stop talking and focus on fighting me, kid.