I have Aegir as Tank, my defense usually keeps me around 2600 cups.
Cups gained mostly by killing other Aegirs with my Rigard/Evelyn/Gregorion/Lianna/Vivica death squad.
Aegir could pose some problems in a war due to hero’s shortage but I doubt that experienced players would lose to him so often in raids.
Seshat is strong, she is fast, hits as hard as Marjana and will dispel his target and nearby foes by doing so on top of gaining temporary health with her minion.
She increases mana genaration speed for all dark allies.
She is really packed with effects and she could have needed a less damaging special or an average mana speed.
But in the end she isn’t too strong, are the old heroes that are becoming too weak.