Idea/Concept

Ritual of Interception: Prevents teleportations in an area and, optionally, teleports them to a different destination.

Interaction

Part 1 - Basics

(Requires a Weak Activation Crystal)

Inventory on top of the MRS for whitelist. A (bound) Teleposition Focus in the inventory decides the destination of the intercepted teleportation (from this point onward "ritual destination point (RDP)").
If the teleportation is a (Teleposer) teleposition, the tier of the Teleposition focus decides which area is being teleposed. If the Teleposition Focus is bound, that player is whitelisted for outgoing teleportations.
An unbound Teleposition Focus simply prevents teleportation.

(If the Teleposer is on top of the MRS, it simply allows telepositions without a destination Teleposer)

Part 2 - Advanced

(Requires an Awakened Activation Crystal)

If additionally, a bound Blood Orb is present, outgoing teleportations for that player (Owner of the Blood Orb) always go to the RDP. In that case, teleportations from other players are not affected.

For (Teleposer) telepositions, the tier of the Blood Orb also limits the area of the teleposition (Weak Blood Orb only allows 1x1 telepositions, Apprentice BO allows 1x1, 3x3, Magician's BO allows 1x1, 3x3, 5x5...).
The Teleposition tier could also be affected by the Blood Orb carried in the main hand when the Teleposer gets activated.
For example if the Blood Orb in the main hand is lower tier than the (already limiting) Blood Orb in the chest and the player would be in the area of teleposition for the Teleposition Focus/Blood Orb tier in the chest but not for the one he holds in the hand, the player "allows" teleposition for everything in the area but doesn't get teleposed himself. For this purpose, any bound item that is not a Blood Orb may suffice (and prevents teleposition of the "owner" even if he/she/it stands right on top of the Teleposer)

Additions could be made to apply effects on a teleportation attempt (A Sacrificial Knife for example would kill the player, a Sacrificial Dagger kills (some) non-player entities that attempt teleporting (whitelist or blacklist might be made)), Negative effects unless countered by an ingredient, a Name Tag for a Message that could be displayed on arrival)

Part 3 - Teleportation HUB

Multiple Teleposition Foci may be present.
If they are bound to the same player, a grammar for teleposition rules may apply (maybe the player needs to carry a X Tier Blood Orb in the off-hand to get to where he wants, otherwise the player is teleported to the RDP).
If they are bound to different players, they are handled just like the rules for a single player.

If multiple Teleposition Foci are present, the first Teleposition Focus that is not followed by a Blood Orb decides the RDP.

Design

The different parts may be three different ritual tiers (every new tier with new additions, for example tier 1 using the elemental runes, tier 2 adding dusk and tier 3 adding dawn runes) or they just depend on what is in the chest and require a refresh by reactivating but should definitly consume more LP (or require additional Will) for advanced functions.

Suggestion/enhancement label or close (should be a seperate addon).

Adding an Enderpearl followed by a Teleposition focus would teleport the Enderman to the Teleposition Focus location, followed by a Sigil of Ender Severance prevents teleportation.

Players can teleport to that location by using a teleposer with a Sigil of Ender Severance in hand.