What team do you use?
If your opponent flanked him with the right crew he should be more than a challenge on an average board and you’ll be half dead before you can fire a special.
Even the worst tank will still beat you once in a while on a bad board so I highly doubt you have a 100% record against Aegir who is up there amongst the blue tanks
Blue mono, dark mono, green mono, 3-2 of those heroes.
The trick is to keep all your combos falling on him until you charge your teams specials. Stray tiles that fall on the flanks and wings will have you incurring their wrath quite quickly.
I use Aegir as a safety blanket against having the flanks and wings go off. Hiding a GM or KGB behind an Aegir tank? Sweet. I’ll keep Aegir alive as long as he useful. Blast either wing with a Panther or Frida unlocks the wing and flank for my specials attack. Kill them and re link Aegirs special to kill the otherside with tile damage without having their heroes use their specials.
Generally I fight Aegir and he goes off several times a fight. I win 9 times outta 10.
If you have Line PM me and I’ll link some fights I haven’t erased yet.