Theoretically speaking,
the equipment named "Vatore's Festival" by his senior truly compensated for all of Annan's shortcomings.
The Shadow Fiend from Kafney significantly boosted Annan's individual attack power in his normal state; while the shapeshifting spell directly addressed the issue of Annan's lack of siege capabilities; "Decree: Dissolve" replenished Annan's rather monotonous attack methods, preventing him from being targeted and countered.
After all, strictly speaking, Annan's regular attack methods were the Radiant Element, Frost Element, along with Dragon Form and the secret Genesis held as his trump card.
...It could be succinctly called the Ice-Light-Dragon Verse.
Under these circumstances, what was most likely to cause Annan's sudden demise was actually his own Brilliant Sword.