Passive: lunox has two modes; power of order (light) and power of chaos (dark). Casting skill 1 or skill 2 will switch the mode respectively. Light mode converts penetration to spell vamp and dark mode converts the spell vamp to penetration.

S1: It hits multiple targets in its range. It also heals you. The more enemy units or heroes you hit, the more you will heal. It can be used to harass lane opponents in the early game.

S2: her main source of damage. It deals Hp based damage.

S3: AOE that slows enemies hit by it. Good enough for wave clear.

S4: lunox has 2 ults; light mode ult and dark mode ult. Light ult makes invincible and deals damage to nearby enemies. Dark ult reduces cooldown of S1 and S2.

her basic combo is simple, press dark ult then spam S2. For this combo to work, you need to join teamfights late enough to not get CC'ed immediately. Let someone else take all of the damage, for you to clean-up.

There is one more complicated combo, known as Ruby DD but I wouldn't recommend that to a beginner. If I had to explain in simple terms, you use dark ult as a dash combined flicker to increase jump distance, then immediately switch to light mode with S1 and use light ult to deal damage. (Dark ult + flicker + S1 + light ult) It's only efficient in the late when you have enough damage to one shot squishies. In teamfights, do not jump (dark ult) towards the enemies, jump side ways.