After Altra made his first appearance, the Companions decided that Karal was in too pivotal a role to be left in the dark. They offered to be a source of information for Karal, especially about Heralds and Valdemar. Florian was their chosen liaision to Mindspeak Karal whenever necessary.
Altra specifically states that he and the Companion Florian are mages. (Storm Warning, Chapter Sixteen) It is not made clear if all Firecats and Companions are mages, or if all have some mage abilities, but only some individuals are true mages. This could be rather like Mindspeech among Heralds. Nearly all Heralds can Mindspeak their Companion, but only a few are true Mindspeakers with the corresponding increase in abilities.
In the series Edit
Florian appears in the following work: