I suppose the Angar-Ryllans would still be interested in stopping some outside invaders stepping on their turf, though half their fleet is at risk of being obliterated by Skallagrim unless Fury stops him. 

Problem is, Fury doesn't really give a shit about the fleet.

The Multiverse doesn't really have many of the high powered individuals required to fight the sort of character's Seed has. I only have two characters in that ultra-high range, one is too powerful and the other would consider the invasion little more than a side-note in his personal struggles against the Dreamer race. 

I say the Multiverse in regards to 'established' characters, which have taken part in the Multiverse before. I'm sure many of you have personal and very powerful characters, but as LeeRoy's Baron shows, they have no real loyalty to the 'Arena' in the fashion of the 'Multiverse' which is the closest thing to the 'Arena' in IC, as far as I can tell. 

Point being, when people invade the 'Arena' the only way they can do so in an 'IC' sense is to invade the Multiverse.

And the Multiverse does not have an abundance of overpowered characters, by necessity of fair-play.