When Spiny Plumes spawn in EX Garuda, it always fixates onto a random player. That player has very high aggro on the Spiny Plume and aggro can't be taken off with conventional means. It must be Provoked.

Once it's Provoked, the original person is still very high on the aggro list and can still pull it back. Provoke alone won't secure aggro, since something as little as popping a self-buff after Provoke can potentially raise his aggro higher than the tank.

Tanks should take extra caution when the original target is a healer since healing enmity can easily re-aggro the Plume. After Provoke, Tanks should hit the plume with something that generates high enmity ASAP to secure it. Flash works well to build enmity if the Plume's HP is dangerously low.

When someone (usually a tank) is ready to have the Spiny Plume Provoked off of him, he should hold off from using any self-buffs for at least a second or two to allow the Provoking tank to hit the Plume at least once.