Kane grandranger: He has the highest stats among those that can trigger others to hit when crit. Furthermore, he can get others to stun and this is important in master level content as enemies can easily kill ur non-tanking units before the skills are ready (you need to disable every enemies and ur best chance is with him and a trigger team). However, being a valiant he is hard to build and you need decent gear (crit must hit at least 60% for such archers)Well I currently have a Vivi.
Current squad is Leon + Sora frontlining.
Vivi/Kane/Theresa in the middle line.
Dont have enough decent archer gear for 3 Archers atm.
Sora has a higher PVE score according to a tierlist, yet you're telling me she is bad?
Can you list why those units are a "must have"?
(http://www.arathos.com/en/ is the tierlist)
Rhea gladiator: In elven form, her attack becomes range with the ability to stun multiple targets reliability. Furthermore, she will gain additional stats and with the fact that she is a warrior, she will have extraordinary attack for a range attacker. Paired her up with a trigger team and she will be an absolute beast, disabling all enemies while dashing out a load of damage. Downside is that she needs two turn to get into that mode, and she can only attack thrice (attack by triggering does not count) before losing the form.
Arthur Holy Defender: Solid defense with his aura. He starts off the battle with a chance of activating a 2 turns taunt, which is really crucial in master stages since your other units are helpless against enemies attack before their skills are ready. Furthermore, his skill has the ability to dispel enemies' buffs, which is important since those buffs are very strong, and also gives a two turns 'invulnerability' to your team, which helps you get past difficult situation.
Cybelle gunslinger: Needed for trigger team. Easiest to obtain and max out.
Gwen gunslinger: Needed for trigger team. Her summon can act as a decoy with high chance of dodging and the ability to silence. Also boosts team attack slightly.
Matilda and Kahuna: Core for SDD team. SDD will help you fight raid 1 bosses easily, allowing your guild to farm gold. Not necessary to limit break,
Victoria and Darrion Chaos Knight: Strong in pvp. They can steal the tiles with their skills and hold the fort with their high defense.
Aden Chaos Knight: Strong in pvp. Provide strong cover to fragile allies with his hp-scaled aura. Take note it's scaled on current hp so if your hp is low, the aura is weak.
Faye Holy Defender: Can protect allies with her strong heal. Skill can also dispels enemies' buff and gives extra hp to everyone. Outshine by Arthur but can be easily obtained relatively.
Shizu ninja/assassin: High base attack stats as compared to other shadows, which allows her to kill enemies easily, especially those behind. Ability to refresh allies is added advantage.
Merlin warlock: Skill deals damage by %hp of enemies and ignored defensive buff, allowing her to kill off enemies with high defense easily. She does not need Mag stats as well, so she can be built into a tank. Her skill recovers her hp by the way.
Freya and Vincent Berserkers: Skills multiply their attack by three, allowing them to deal super high damage for three turns. I have reached 100k damage on my freya before and I have yet to count in the bonus splash damage. However, their long skill cool down is a serious disadvantage.
As to why I don't considered Sora good is that the shadow class in general are not useful in master level content unless you boost their attack significantly to at least 15k, which is kinda hard for their stats spread. Moreover, Sora's aura chance has an activation chance of only 35%, which is low as compared to archer's max 70+%, so she effectively stops your team from chaining more attack while dealing little damage. Her pet is good though since it can hit the backline and can swap in a unit there directly, but that's all to it. 60% dodge is good but she is probably dead before she can even use her skill in harder content. Nonetheless, she is still worth investing if you don't have better unit. Once you reach late game, you will have sufficient resources anyway.