Crown

Regarded as a top-tier Burst 2 supporter in Campaign, bosses, and Raids.
If the lineup leaves your main DPS without her ATK buff, her value collapses at once, so you have to set Burst order and lineup by hand.
In Arena and other real-time PvP modes she fits worse than alternatives of the same tier.

Her Machine Gun normal attacks can detect enemies that are hard to auto-target and deal a higher ratio of damage to cores.

When Full Burst Time begins, One for All1 grants all allies who used a Burst Skill just before it Increased ATK based on the caster's ATK plus Increased Reload Speed, and grants all other allies Increased DEF based on the caster's DEF plus Increased Reload Speed.

Royal Attire2 stacks Relax (increased HP Potency) on herself every 43 normal attacks. At max stacks it clears them and grants her invincibility, Taunt (taunts all enemies), and HP recovery proportional to the caster's final max HP. When that healing applies, all allies gain an Attack Damage increase.

Last KingdomB grants all allies an Attack Damage increase and a shield proportional to the caster's final max HP. Her Burst cooldown is 20 seconds.

Auto play is enough by default.
At a low display frame rate, the per-second interval of normal-attack hits changes, so Royal Attire2 stacks feel like they build at a different speed. If it feels inconsistent, raise the frame rate or time only your reloads by hand to keep normal attacks continuous.

Reload Speed and ammo capacity/refill directly affect Machine Gun ramp-up and Royal Attire2 stacking. If Harmony Cube levels differ a lot, use the higher-level cube over the theoretical ranking.

Because she gives Increased ATK based on the caster's ATK, it is hard to drop ATK lines entirely, and Max Ammunition Capacity helps stabilize her normal-attack cycle.

Level One for All1 first for the reload buff and Increased ATK based on the caster's ATK. Last KingdomB carries a large share of Attack Damage and shield value, so raise it right after. Royal Attire2 combines invincibility/taunt and an Attack Damage increase in one skill, so you can keep it low early and fill it in later.

Strong in Campaign, bosses, and Raids as a tank who brings buffs, a shield, and taunt all at once. The same premise holds in Tribe Tower. Low priority for Arena.

Each Full Burst brings split ATK/DEF buffs and Reload Speed, plus Last KingdomB's Attack Damage increase and shield.
She overlaps taunt and invincibility in the same window, covering survival and aggro at once.
Her normal attacks can hit enemies that are hard to auto-target.

Increased ATK only goes to allies who used their Burst Skill right before Full Burst, so depending on the lineup you have to plan around cases where it misses your main DPS.
Some heals and buffs are not processed as healing, so they do not trigger Royal Attire2's Attack Damage increase.
How fast Royal Attire2 stacks up feels different depending on your display frame rate.

Even if Red Hood covers both Burst 1 and Burst 3, the ATK buff from Crown's One for All1 does not stack twice.