Sabre and Katana specialty means he benefits greatly from common Earth Omega grids
Weaknesses
No team utility outside of providing team members with additional charge attack bar from his constant charge attacks
Reliant on other characters for DA/TA buffs
Extended Overview
As character released shortly after launch, Aletheia comes with a simple yet effective kit. His damaging skills do decent amounts of burst damage, and can be further strengthened by his Charge Attack's effect. Aletheia is also well equipped to fire off charge attacks often as he has C.A. Instant Standby on a 6 turn cooldown, as well as increased charge bar gain from his Holy Sword support ability. He excels in short fights and solo content, where his high skill damage numbers can make quick work of mob enemies, as well as deal up to 1.2 million damage from a single skill use after a Charge Attack.
With Sabre and Katana specialty, he get great gains in stats from being used in earth's Omega grids, whether it's the basic Yggdrasil Crystal Blade Omega based grid, or much later with Nibelung Klinge based grids. Being Attack type and Human race gives him access to 2 nodes of DA and Crit innately, both of which are high priority on any character. Aletheia's individual perks give him options to either raise the amount of damage his skill and charge attack does, or increase the max amount of damage either can do. A player starting out can start off by giving him stars in Skill Damage and Charge Attack damage to reach higher numbers, and then move those stars to their respective damage cap up nodes. His support skill is unfortunately underwhelming compared to his other options, since there is no way to guarantee that it will proc.
Unfortunately, his one-dimensional kit can cause him to fall off in harder content. He has no methods of team support, outside of providing team members with additional charge attack bar from his constant charge attacks. He also has no methods of raising his own stats on his own outside of his EMP, notably his DATA rate, and will have to rely on other characters to raise them. Despite this shortcoming, Aletheia is still a very potent and simple to use character who can unleash great amounts of burst damage consistently.
How to Play
Place Aletheia in the 4th position. Use his Speed ability after a chain burst and have him Charge Attack by himself to give the rest of the party a 10% boost to their charge bar. Use his first two abilities whenever they are off cooldown.
It is advised to prioritize Aletheia's C.A. Damage points first, followed by the other recommended points. Afterwards, consider his Attack and/or Critical nodes for the final six points.
This build optimizes his Extended Mastery Perks for burst damage. As a result, Skill DMG Cap and C.A. DMG Cap should be the first two priorities. For less-developed grids that aren't yet hitting the C.A. cap, the two C.A. DMG nodes should be prioritized first. Both Critical nodes should be raised to 3★ to raise his overall damage potential.