This unit is pretty much under hyped as she doesn't have any uses currently with the physical slash/missile meta this early in the GL(global) server and people disliking that she's limited. Most people are investing into raw physical damage this early in game since it's easier to 🔥 with no one having access to good physical armor with high def. However once physical resistance tanks with high def becomes the meta those physical slash/missile attack will do 0-100 damage on enemies with around 5k HP. People will need to start to switch over to magic attacks and Fryevia will shine as a tanky spell blade with green/white mage sub jobs that supports/revives/heals her team from the back while being able to cause magical slash damage to anyone who gets near. Her downside currently is sustainability due to the fact that she only has access to heavy armor this early in GL. So people using Fryevia currently are running around with no armor/weak armor in PvP, that's why people think they're not tanky. Currently only gold and mythril armor (with a few TMRs) are available for her, however, later on she will have access to WoL's armor which will be able to add +8% resistance to magic and give her def/spr for physical/magical attacks and better TMRs. Being a support tank also means more investments since supports have way more casting skills than attackers and their resistance needs to be built with good/high lv espers, vision cards, armor, and accessories to be viable as compared to an attacker roles which only needs to focus on high raw attack/magic which could be easily obtained from a +5 assault/magic weapon. Most of her casting skills currently haven't reached lv 20 yet so we won't know Fryevia's full potential in GL until a month or two more since she's time consuming to build as tanky spell blade with green/white mage sub job and GL still stuck in the physical attacks meta with barely any magic attacks.
the idea of having a tank that can do great support and heal is very interesting indeed, but i think her main problem with that is that she don't have a good way of generating hate when using sub green or white mage since taunting spell is not her main skill and her speed is rather low. i think she will not be a good magic tank and support, but a good magic tank OR good support unit.
The only problem is that she will literally not cast Raise and Full Life as long as Protect/Shell are in her available AI pool of skills. She will probably be way more useful once we can disable those two skills. And her heals are funky, too. Otherwise, she's a great magical tank with utility.