Fenris would likely be both impressed and a bit cautious of the Elf Inquisitor's abilities. His own lyrium - infused powers are quite different from the Inquisitor's magic or combat skills. He might see the Inquisitor's ability to control the elements, for example, as a powerful but also potentially dangerous force. The Inquisitor, on the other hand, would be curious about Fenris's lyrium markings and his superhuman strength and speed. They might initially test each other's limits in a non - hostile way, like during a sparring session.
Fenris would be very observant of how the Elf Inquisitor uses their abilities. If the Inquisitor is a mage, he would be watchful for any signs of corruption or overreach, given his own experiences with mages in the past. However, if the Inquisitor uses their powers responsibly, he could come to respect them. The Inquisitor, seeing Fenris's unique abilities, might see him as a valuable asset in dealing with threats that require brute force. They could end up having a mutual admiration for each other's skills as they face different challenges together, like exploring ancient ruins filled with traps and enemies.