Ollie (Osiris) is a 5 stars Flow Fighter esper in Dislyte.

Osiris is a good offensive unit that has some support built in. His kit revolves around protecting 1 ally from death and counter attacks the enemy that killed your ally. This is quite useful in story mode against very tough enemies or in PvP as well. His skill 3 basically gives him invincibility and taunts the enemy + defense break. If you are in need of a defense break esper, he would be a great addition.

His skill 1 can silence an enemy, which is mostly used for PvP. Due to his single target kit, he doesn't offer much AoE and will not be used in cleave teams.

For PvP, he guarantees one of your units to at least survive 1 round to do something unless they are crowd controlled. His speed leader skill is also very good here. Another thing is that his passive has a long cooldown, so if you have a good ocean waves set, it can be used to lower his passive skill a bit faster, especially in long battles.

For builds, he can be built full support or a damage dealer. He is versatile and has good base stats for both roles.