names are negotiable

Sigil of Impotence - prevents enderman teleporting and creeper exploding nearby at a ongoing LP cost. insertable into bound armor. (maybe split in 2 sigils or as ritual?)
Custom Ritual Diviner with a GUI to select the rituals from a list.
Sigil of Burden - locks every living entity around the holder in space, including himself. ongoing LP cost. (maybe make it really LP pricy to keep players from trolling others for hours by afking - or make it turn off/break on its own)
Sigil of fuckup - makes every creeper that comes in range instantly blow up. ongoing LP cost.
Sigil of peace - mobs around you will not try to attack you while it is activated. No LP cost. but it will kill you when attacking a mob.

to be continued.

EDIT: Sigil of creation - make mobs spawn around you using the local spawning possibilities. passive and agressive mobs all the same. LP cost per spawn

going to implement several of these ideas, but most work will be going into the 1.8.9, may backport, maybe not

I noticed the Ritual of Satiated Stomach only keeps your food level. So maybe make a custom one that also fills it?