4e Dimensional Anchor

[HMS Invincible]

I need something that I can use to stop someone from teleporting (unknown DM fiat, casts in less than 1 round). I normally wouldn't care since recurring villians are recurring, but the GM is pulling out all the stops by giving us a blood oath of kill said villian by set date or be killed by the blood oath. The item dimensional anchor is great except its a stupid lair item instead of the portable target spell from 3.5 .
Got any Ideas/items/rituals?

[Kurald Galain]

Orb of Translocation Interference.

[illyrus]

I'm betting 5 gold that the NPC will have an immunity to anything that stops them from teleporting. If they're opening up a portal in a round and not just winking out of existence I'd ask for a perception check on the rune combination on the ground of their destination and hope it's their own lair so you guys can go defeat him after going thru the GM approved dungeon/mansion crawl.

[Tiki Snakes]

I'd say probably the best way will be to somehow do enough damage in a single attack (or at a push, round before his initiative) to drop him. This may be tricky, but gets around issues quite well.

If he teleports out automatically at a certain hp level, reguardless of whether it's his turn, just ask the dm nicely where the macguffin he wants you to find to kill him might be hidden.