Identify this fantasy series [duplicate]

Question

I read this series around 1994. The protagonist was a boy who could summon elemental magic, or maybe it was just that he could summon elementals - I can't remember. A companion of the boy, an old man, was some kind of wizard or magic user who had a phoenix as a familiar. Another of the boys companions obtained a sword that could absorb the souls of its enemies. I think much of the series consists of the boy and his companions battling demons. I think the boys elemental magic makes the demons weak when they are in its presence.

At the climax of the series there is a battle between the old man (wizard) and a powerful demon made of diamond. The boy is also here but is unable to summon his elemetal magic because the substance the floor is made of prevents it. The old man is lying on the floor, almost dead, and scratches some symbols. The old man cries out "Uriel" and the angel Uriel is summoned. Uriel askes the demon why he has summoned him. The demon says, "I did not summon you, the old man did." The demon happens to be Uriel's most hated enemy, and Uriel is happy to finally find him alone, without backup. So Uriel and the demon battle and the demon is defeated.

Can anyone remember the series this is from?

Answer 1

Not sure if it's correct or not, but Douglas Hill's Blade of the Poisoner (first published in 1987) and presumably the sequel Master of Fiends hits several of the high points.

There are not any good summaries online so I will link to this question which has an answer that links to several other questions that each have their own summaries. My synopsis of the first book, since I haven't read the second is below.

Jarral returns to his village to find it destroyed by the evil prince. He is captured and injured by the prince's magical, poisonous blade so that he will die in 30 days. He meets up with the Giantess (?) named Archer who helps him escape. She tells him that she works for a wizard who opposes the king, and more importantly the evil power behind the king.

We also meet Scythe who is blind, but a master swordsman. Turns out he has the special ability to "see" in all directions mentally. He also works for the wizard and is sent to help Archer and heads out. On the way, Scythe meets up with Lady...M (can't remember her name) who is a young girl with the Talent of mental manipulation of others. The 4 meet up and decide to travel to the Prince's city to try to destroy the blade and save Jarral. The wizard is involved in this decision at some point.

Lady M uses some of her power to keep Jarral calm. She can also make it so others do not see the group. During their travels, Jarral discovers he has some Talent to control elements. At some point, an evil bird demon catches them, and the wizard's good bird familiar helps to save them.

After infiltrating the city, the 4 confront the prince and the wizard comes out of hiding to help them. During the battle, it is determined that Jarral actually summons elementals and that they are the only thing that can really kill demons since the presence of elementals weakens them. I believe the wizard is captured by the Prince's boss and the 4 vow to save him (in the second book).

Other details, I don't know. I think I remember reading something about the end with someone cutting into their own hand, not the floor. Uriel as a character--no idea. Medieavla--?? generic fantasy, so sorta.