Only 3 out of the seven sister’s are viable those being Taygete, Kelaino, and L’kian. Kelaino is used in every Cassyva list, Taygete in most Vaath lists and L’kian in almost every list. The others sisters see practically no use at all whatsoever and here are my suggestions:
Sun Sister Sterope current text: Whenever ANY minion or General is healed, put a True Strike into your action bar. There is almost no point to using Sterope with Sunriser around.
Sun Sister Sterope suggested text: Whenever ANY minion or General is healed, put a Lucent Beam into your action bar. Making these changes will help define the healing arch-type in Lyonar .
Wind Sister Maia current text: Whenever you summon a minion with Infiltrate, give it +1/+1. Maia’s ability is completely useless as you are not running most minions with infiltrate.
Wind Sister Maia suggested text: Whenever ____, summon a 0/1 well with provoke nearby. Maia’s ability is completely useless as you are not running most minions with infiltrate. Having her summon a wall whenever triggered helps Vanar generate walls outside of summoning them or White Asp. This is really helpful for wall decks and would give a small incentive to using Kara over Faie in wall decks and I would suggest the ability allowed to be triggered more than once in your own turn(EX: Four Winds, Kelaino)
Storm Sister Alkyone current text: Spells you cast that deal damage deal +1 damage. Crescent Spear does Alkyone intended job much better.
Storm Sister Alkyone suggested text: Whenever you cast a spell that does damage this minion gains attack equal to the damage dealt. This will help the Spellhai arch-type giving it a “high”(I say high because this will probably be the highest mana cost card in the deck besides Heaven’s Eclipse) cost minion to synergize with cards like Ghost Lighting and generate a huge body indirectly. Songhai is great at developing threats and forcing you to take them down before they get too big and this does just that.
Sand Sister Saon current text: Your General has +1 Attack. Has little on board effect and dies too easily for good usage. 4 mana is a lot to have a 3/4 that does nothing but give your general attack until it dies.
Sand Sister Saon suggested text: Opening gambit: Your general gains +1 Attack. Works similar to Falcius as it gives your general a buff while still creating a body. This will help Sajj develop bodies while still making use of herself as a weapon.
Most of these changes are to help arch-types that are inferior compared to others in the faction. Obviously, if these changes were to happen some stats would have to be altered to have a healthy, balanced card. Curious to see what others think of these suggestions.