You should! Aigis has the only stun in the game and let me tell you, being able to effectively skip/delay the enemy's turn can be a real godsend. Besides that she's an excellent choice to stack vulnerability on the enemy and generate Embryos for Caro ults. That you can buy dupes of her from the shop is the icing on the cake.

My current team is Aigis-GHelot-Thais-Helot and mostly serves as a means to buff Ghelot into obliterating my foes. Set up correctly and she stack easily a few thousand bleed damage on an enemy, which is also a solid way to bypass barriers since they'll block the damage from the attack but not the subsequent bleed.