I'd say that Tyr defines Thunder entirely into a "Burst your enemy down during Stun" element. Tyr is also the only KH in Thunder who has a proper debuff... if you can call 10% a proper one, 15% when awakened. That makes Thunder struggle, as you're entirely reliant on your Soul for debuffs.

Either that, or Thor for Paralysis.

Near the end of January, Mardook will have -20% Atk at least. C frame too. That's just barely in range of the second Miracle ticket, I guess.