Reverse Polarity pulls enemies together and stuns, so Blink in and cast it on a grouped team.

Empower gives your carry cleave and bonus damage, so keep it on them for faster farm and fights.

Shockwave damages on the way out and back, so position so enemies walk into the return hit.

Skewer drags enemies with you, so use it to pull a target into your team or tower.

Shockwave provides vision and hits invisible units, so use it to scout and reveal.

Magnus falls off without his ultimate, so time your Reverse Polarity for the fight deciding moment.