Focus? Definitely an epic fantasy take with PCs ultimately being forces for/agents of Law, Chaos, and/or the Cosmic Balance.
Icons would be the Lords of Law and Chaos, possibly the Cosmic Balance, possibly Fate, and also the Elemental Lords.
Classes would be the existing barbarian, commamder, fighter, ranger, and rogue. Custom class would be a sorcerer built on the druid chassis so that the choice of talents would model a range of classes. The animal companion talent serves as an excellent starting point for summoning creatures and even binding them. The Icons would also determine spell access as is the case with the occultist and I think the spells would otherwise be conversions of what exists in MRQII.
Two races: humans and Melnibonéans. The former would be touched by Fate and thus lucky. The latter would have a bonus sorcerer talent. With some work, this should balance them against each other while feeling very different.
I do like the various d100 versions of Elric and Stormbringer but there's a lot of work for the DM when it comes to creating monsters and NPCs which is not the case in 13A. That's my primary reason for wanting to go this route.
Anyway, I'll keep reading the 13th Age version of Glorantha to see what other things might jump out at me.