Eunectes's traits, talents, and skills at E2 M3 for all the skills:
Trait: Only recover SP when blocking
Talents: When HP is higher than half, ATK causes 115% damage; when HP is not higher than half, gain [Shelter] (physical and arts dmg received is reduced by 20%) (only the highest affect is taken)
Skill recovery speed when blocking an enemy +0.2/sec
Skill 1: Atk + 25%, Def +25% [passive skill]
Skill 2: Attack interval of <@ba.vdown> slightly increased, attack power 180%; Continue to stun all blocked enemies during the skill [manual trigger] [18 sec duration] [sp cost 28, initial sp 15]
Skill 3: Atk +230%, Def +160%; block +2; recover 6% HP per second; <@ba.rem> stuns itself after the skill ends for 5 sec [manual trigger] [35 sec duration] [sp cost 45, initial sp 25]
^ Based on this and her high stats, Eunectes looks like she's basically a duelist guard that turns into a defender with her 3rd skill.