The Kinslayer achievement requires you to start as one of the Russian region minors with a Rurikovich ruler, be the sole nation with the Rurikovich dynasty, most significantly, this will usually mean removing Muscovy unless they get a different dynasty on their throne. Note that you only need to start as one of these nations. I got the achievement after I had switched from Odoyev to Ruthenia.
- Main article: Tver
Tver is one of the valid start options, and have the advantage of starting independent of Muscovy. They share borders with Muscovy, their vassal Yaroslavl, and Novgorod, the last of which will probably be the first area of expansion. One strategy is, if you can get an alliance with Muscovy before they declare on Novgorod, then you may be able to call Muscovy into a war against Novgorod, promising land, which you do not intend to give them. Taking land from Novgorod such that you border the Livonian Order will give you a second target, who may prove easy pickings depending on the timing of when Poland tries to go to war with the Teutonic Order, with whom the Livonians are usually allied.
Another strategy would be taking Muscovy head on. Ryazan should not be allied, as they will not attach Muscovy. Good choices for allies are Novgorod and Great Horde. If lucky, Lithuania will not PU Poland and can be used as a great ally to bump up the army quantity. Focusing on Military Technology, and developing territory to increase army size should be sufficient. The earlier Muscovy is attacked, the better. It is best to destroy their economy than army. If multiple territories are cored, Muscovy will be able to maintain army of 50k+ (with vassals), and may come back stronger in following wars.
- Main article: Ryazan
Ryazan is one of the valid start options and start with the greatest total development. They have the advantage of starting independent of Muscovy. They share borders with, Lithuania, Great Horde and Odoyev. They start able to rival Odoyev and have easy access a mission granting a claim on them, making them a logical first target for expansion. It is often possible to declare war on Odoyev before the Golden Horde, Muscovy or Lithuania, either warn you or guarantee/ally Odoyev. From there you have choices. Usually you will want to ally Muscovy, and use them to declare on the Golden Horde, or possibly Lithuania (especially if they are not in a PU under Poland). From there, switching to Sunni may be advisable, and expanding down to the Caucasus until you feel large enough to take the fight to Muscovy. If Lithuania are not forced into a PU under Poland the situation is even more complex as you may even wish to ally Lithuania rather than Muscovy, and try and use Lithuania's rivalry to help you to destroy Muscovy.
- Main article: Yaroslavl
Yaroslavl is one of the valid start options, and start as a vassal under Muscovy. They share borders with Muscovy, and Tver. A first step as Yaroslavl would be to achieve independence from Muscovy, which will almost certainly require support from a similarly large nation. This will usually be their rivals, such as Lithuania, Novgorod, and Great Horde.
- Main article: Odoyev
Odoyev is one of the valid start options. They are a single province nation inconveniently situated between Lithuania, Muscovy, Great Horde and Ryazan. The latter usually being their only option for early expansion assuming Ryazan won't get any allies, they are however usually either allied to Muscovy or guaranteed by the Golden Horde. If the player is able to ally either Muscovy or Lithuania (the latter being unreliable because it could enter a PU under Poland at any time) and manages to either gain 10 favours or the formerly mentioned nations want land from each other they can call them into a war against the other either in exchange for favours or by giving them one province in the peace deal. It is highly recommended to actually give the ally a province, as they will be needed for a second attack around a decade later. Additionally, playing as Odoyev gives the player the opportunity to earn the Mass Production achievement (starting as Odoyev, own at least one manufactory of each type).
It is generally recommended to keep track of the movements of great powers around the Russian region, usually these are Muscovy and Poland. Alternative great powers that could be around are Lithuania assuming Poland didn't get its Personal Union over them and Novgorod if they manage to beat Muscovy. The player might try to become friends with one of these nations so that they might help crushing the player's kinsmen. When not playing Yaroslavl it generally doesn't require much attention, as Muscovy is likely to inherit it eventually anyway.