Phoenix Sigil
Corin makes several of these for himself and his friends, improving on their design as he progresses. Originally they just created a second shield outside that created by the School-issued Shield Sigil[1], but he later added several additional functions to them.
Design
Corin's phoenix sigils have been through several iterations, growing in power and complexity as his skills as an enchanter improved.
Initial Design
Corin's initial phoenix sigils, designed for his friends to use in the second fake spire exam. This initial iteration was made of copper and were a more powerful version of the school-issued shield sigils with a self-recharging function[2].
Silver Phoenix Sigils
Prior to the final first-year exam, Corin made a new version using pure silver due to the increased enchanting capacity. This extra capacity was used to double the shield's power, and to add a regeneration effect[3].
Anti-Tampering
After his final exam, Corin added anti-tampering runes to his phoenix sigil, so only he could make modifications to it[4].
Mana regeneration
Prior to climbing the spire in search of his brother, Corin adds a mana regeneration function into the phoenix sigils[5].
Jump Bell
On the train ride to Caelford, Sera helps Corin upgrade the shield sigils with low-quality jump bell enchantments, which required anchors and had a very short range[6].