Create a vertical **sci-fi weapon concept design poster** featuring a futuristic **Modular Energy Spear**.
Use a deep **electric blue and violet background** with subtle geometric patterns. Place one oversized weapon diagonally across the composition, taking up most of the canvas. The weapon should have a sleek mechanical silhouette, dark graphite metal, silver edges, small gold details, and glowing cyan energy parts.
Behind the weapon, add huge cropped decorative typography:
**VANGUARD**
At the top left, place a small technical label:
**TACTICAL EQUIPMENT / UNIT 07**
On the right side, add the main title:
**ARC SPEAR**
Subtitle:
**Adaptive Combat Weapon**
Below it, include a short English description explaining that the weapon can switch between a compact mode and an extended spear mode.
At the bottom, create a small **FUNCTION DEMO** panel showing three simplified weapon states arranged horizontally:
**COMPACT → DEPLOY → ENERGY MODE**
Add small arrows, technical icons, and short UI labels.
Style: premium anime game concept art, futuristic industrial design, clean editorial layout, sharp cel-shaded rendering, metallic material details, bold typography, blue-violet color palette, subtle technical UI graphics, high-detail weapon presentation, polished game artbook aesthetic.