We know that only something not native to the world (something otherwordly) or divine can harm a demon. On Sennadar this means weapon made from material which origin is from other world, and is not native to the world, like Ironwood, adamantium or the black no-name material Tarrin's sword (and his Cat's Claws after transmutation) are made of; Arcane energy used by Wizards (or stolen from the Weave by the Sorcerers like in the battle of Suld); priest spell of Banishment and God icon or demigod itself (Tarrin's wings). Druids of great (Hierarch's) power can also harm demons by requesting the All to do something otherwordly. On Pyrosia this also means Sorcery, as it is alien (and energy is alien) to this world. I wonder whether Elemental magic on Sennadar (if it would be possible to use it there) would be dangerous to demons: on one hand Elemental magic is alien to Sennadar, on the other hand the four elements (the energy) are not. The bodies of demons have also to obey the rules of physics, so physical force can do them harm too. But one must remember about demon's innate antimagic...
Still ShazBaket was Banished by Tarrin during the battle of Suld and returned back on Val summoning. Do banishment prevent permanently the demon it was used against to enter the world it was cast on, or it only sends demon back to "Hell"? (And one have to rely on the fact that demons cannot pop "uninvited" to the world; they can only enter via gate/portal or be summoned). Was it important that it was God (Val) who summoned X again to Sennadar? I have the feeling that ShazBaket hinted during talk with Tarrin on Pyrosia that she cannot enter Sennadar ("Sword of Fire", Chapter 6), but I might be reading to much to this conversation. It might be that there are noone to summon her to Sennadar; it might be something more.
The body of ShazBaket was crushed under stone slab during the fighr with Val in the "Weavespinner". Whether it killed her body or just trapped her I don't know. Are demons killed using otherworldy weapon or magic destroyed permamently or just go back to "Hell"? It seems that at least half-demons (like Shiika cambisi) when killed, they are killed. Are demons which body was destroyed or maimed by physical force destroyed permamently or just go back to "Hell"? The case of ShazBaket hints that it is the latter.
So maybe imprison her using some variation of Wizards spell used to "convince"

I hope that Tarrin did not forget that ShazBaket lives and is after him... and he has no access to his divine powers... It is not safe.