Githzerai Planewalker

Paragon Tier
Prerequisite: 11th level, githzerai
Benefit: When you perform the ritual Linked Portal, Planar Portal, or True Portal, you halve the time required to perform it and gain a +5 bonus to any required skill check. In addition, you can master those rituals even if you don’t have the Ritual Caster feat.

Published in Player's Handbook 3, page(s) 188.