
Thanks for the suggestions. Seems like I was in a completely different ditch when it comes to Achatin; I had imagined them as mostly White, but I must concede most of my impressions of them were from their warfare against the Uld'ar where they seemed reasonable enough.
I was planning to narrowly include the Pure Aifons, yes. Just a couple of cards, really.
@Kyzark: I think the two largest differences from back then (I'm an old magic player as well, who just recently refound the game) is that the power curve is slightly higher (cards are more powerful compared to back then, in general), and the plenty of new mechanics.
@Terrence: I was thinking of including the kaers as special lands: They would come into play with some (two? three?) "Time counters" on them, and may not be used before these are removed (one each upkeep, ideally). They would be able to tap for two different mana types, like this...
Sjykalfar Kaer: Black/Blue
Baal Kaer: Black/Red
Tabba Ghut Kaer: Red/Green
Asgalfar Kaer: White/Blue
Pilsetan Kaer: White/Green
I am thinking, maybe it will make the cards too complicated, but an alternative to waiting for the counters to be removed is to pay something else, like this...
Sjykalfar Kaer: Black/Blue - discard top 3 cards of library
Baal Kaer: Black/Red - take 3 damage
Tabba Ghut Kaer: Red/Green - target opponent recieves 3 life
Asgalfar Kaer: White/Blue - tap a land you control. It does not untap next untap step
Pilsetan Kaer: White/Green - put a 1/1 green Saproling into play under the control of target opponent
It might also be possible to create some rarer kaer lands for the non-ally combinations;
Palatinate Kaer: White/Black
Throalic Kaer: White/Red
??? Kaer: Red/Blue
??? Kaer: Black/Green
??? Kaer: Blue/Green
And of course legendary lands like Achatin, The Ebon Palace, The Patrian Kaer, and so forth.