Yetis cost less mana and they get a boost to atack and atack speed. Sednas yetis should draw or complement Sednas abilities, they already have high Hp to get the most out of sednas regen why not give them a better atack to create a sedna minion auto atack build (Although something in my head is screaming OVERPOWER!).
Well here are somethings that might help:
1-20% of damage to sedna goes to Yetis.
2-Yetis gets higher armor and regen.
3-The ability to force minions to atack them.
4-They have a 20% chance to take the damage dealt to sedna by a skill.
5-Yetis create a atacka speed reducing aura.
I guess the key to the Sedna Yetis issue is what skills is sedna surrendering to get Yetis, cause in any other demigod Yetis would be ok but sedna has so many great skills that they look like crap, so i guess they should be balanced to make them a counter, and the only thing she needs to counter is minion builds cause of her lack of AoE.
Hope i helped.
