Does Taric grant Fiora the Mighty keyword when they are both at a battlefield, making her 6 might instead of 5?

Ruling: Yes, Fiora becomes 6 might while defending with Taric at the battlefield. Taric grants her the Shield keyword, which increases her might to 5, making her Mighty, and then she gains +1 might from being Mighty.

Sequence:

• Taric grants Fiora the Shield keyword
• The Arithmetic layer applies, seeing Shield and increasing Fiora to 5 might
• At 5 might, Fiora becomes Mighty
• The layers loop again and she gains +1 might from being Mighty, reaching 6 total

Nuances:

• If Taric leaves at any point during the showdown, Fiora drops to 4 might (assuming no other might alterations)