cap 'n chris said:
Pendant!
Probably "evoke" rather than "invoke"; otherwise the person engaged in the magic would be trying to get themselves possessed!
No - invoke.
One chants an invocation.
However the two have very similar dictioanary definitions with some overlap making both words valid in this case - differing only in common usage - the correct expression in this context is to invoke.
http://dictionary.reference.com/search?q=invoke&x=33&y=10
verb (used with object), -voked, -vok·ing. 1. to call for with earnest desire; make supplication or pray for: to invoke God's mercy.
2. to call on (a deity, Muse, etc.), as in prayer or supplication.
3. to declare to be binding or in effect: to invoke the law; to invoke a veto.
4. to appeal to, as for confirmation.
5. to petition or call on for help or aid.
6. to call forth or upon (a spirit) by incantation.
7. to cause, call forth, or bring about.
http://dictionary.reference.com/search?q=evoke&x=27&y=15
verb (used with object), e·voked, e·vok·ing. 1. to call up or produce (memories, feelings, etc.): to evoke a memory.
2. to elicit or draw forth: His comment evoked protests from the shocked listeners.
3. to call up; cause to appear; summon: to evoke a spirit from the dead.
4. to produce or suggest through artistry and imagination a vivid impression of reality: a short passage that manages to evoke the smells, colors, sounds, and shapes of that metropolis.