Ritual of the Three Circles (3.5e Invocation)

This invocation has three uses, each one having a specific ritual needed to perform which require drawing a circle on a flat surface for a time (based on the circle) and then do a 5 minute ritual while adjacent to the circle, which including somatic and verbal component,

Circle of Travel: The first use is to make a travel version of gate that lead to any of the lower the plane, it appear where the circle was placed. The catch is that the gate only stay open for 24 hours, after which point it will close on both end. Since you cannot create gate to anywhere else but the lower plane you may be left trapped.

This circle require 24 hours to draw and a secret DC 30 spellcraft check (which may increase at the DM's discretion depending on where in the lower plane you want to travel to). Failing the spellcraft check do not make the ritual fail, instead the gate will open to another location on the same plane (most likely on a different layer).

Circle of Fiendbind: The second use allow you to summon a fiendish creatures as per summon monster, the level of the summon monster effect is based on your effective warlock level for casting invocation (your are not forced to use the strongest version available). The creatures appear within the circle and are under your control. Unlike a normal summon monster spell last indefinitely but the summoned creatures are freed from your control after 1d4+1 hours, at which point they count as called creature (and cannot be dismissed) rather than summoned creature.

This circle require 10 minute to draw and secret DC 10 +twice the summon monster level spellcraft check. Failing the spellcraft check do not cause the ritual to fail, but instead all the summoned creatures are hostile to the caster on arrival and gain a surprise round on her.

Circle of Calling: The third and riskier use of the invocation allow you to call any outsider with the evil subtype, even unique ones. If the outsider's CR is equal or above your character level it may decide to ignore your call otherwise it is brought into the world without a choice into the circle. The fiend is never under your control, it is 'called' as if it moved to your plane through plane shift and may be unable to return home by itself.

This circle require 1 hour to draw per CR of the called fiend, it does not require any spellcraft.