The current roster has six Mythic parts, acquired through Gem forging or a rare late boss-crate find. Evaluate their mechanics, weight and resource fit before replacing a part in an already working machine.
Know the acquisition route
The item reference distinguishes 57 non-Mythic parts from six Mythic definitions. Campaign starter and first-clear unlocks cover the non-Mythic set. Mythics use a separate Gem-forging route or the published rare late boss-crate chance.
The documented late boss-crate chance is 0.4%. That is a chance on an eligible crate, not a promise after a fixed number of opens. Read the current in-game pool and offer before spending; a crate outside the eligible pool is a different reward.
Read the mechanic before swapping
Storm Blade combines melee pressure with a core-only arc. Gravity Cannon combines a shell with pull and attachment damage. Aegis Matrix adds a defensive interaction, while Omega Reactor supports energy and weapon output. These roles still need compatible range, weight and behavior.
A new mechanic can change the whole machine. Adding a projectile to a build facing reflection, or replacing movement support on a pursuit build, can create a problem despite the higher rarity label. Test the replacement in a familiar matchup.
Keep the rest of the build honest
Ranked Arena normalizes attachment levels but retains mechanics. You still need a legal loadout, useful movement and a plan against the opponent’s defenses. A Mythic does not remove those requirements.
If you are early in Campaign, first-clear counters and practiced Dash timing are accessible ways to improve now. Treat Mythic collection as a longer progression goal while continuing to refine the equipment you already own. The most useful next item is the one whose mechanic addresses a specific gap.