Spells

Planescape includes a variety of setting-specific spells. I haven't found any 5e conversions, but many 2e spells are generally usable "as is" (e.g., when no damage is involved). Warp Sense is very useful to planewalkers. Casters may also be particularly interested in:

• Gate Seal
• Gate Ward
• Portal Alarm
• Portal Beacon

Here's a nice 3e conversion of all the spells: http://www.enworld.org/ericnoah/conversions/planewalker/spells.html

(I have the 2e Planewalker's Handbook if we need the original source.)

Haelra's Chains

Level 2 Necromancy
Casting Time: 3 rounds
Range: Touch
Components: V,S
Duration: Concentration, up to 1 hour

You touch a creature which has two of its wrists or ankles touching (e.g., together, crossed). Its wrists or ankles may be in front of or behind its back. If the creature moves it wrists or ankles while you're casting the spell, the spell fails.

The target must succeed on a Constitution saving throw or have its wrists paralyzed and connected (as if by glue) for the duration. Every 1 minute the target can make another Constitution saving throw. On a success, the spell ends on the target.

At Higher Levels. When you cast this spell using a spell slot of 3rd level of higher, you can target one additional creature or pair of wrists or ankles for each slot level about 2nd. Each creature must be touched while you're casting the spell.