The ShiftstonedEternal Power Calculator is a deck-building tool that visualizes your odds of drawing enough Influence and Power based specifically on the cards found in your deck.
Steyer's Eyes is a good replacement for Copperhall Porter. He synergies with Icaria too and gives single target spell sustain. I also included Kira in my version. Have won every iteration I've played.
I replaced Svetya, Merciful Orene with Martyr's Chains. It sped up matches where enemies were able to stall and is satisfying to use when you play 3+ sigils at once.
It depends what deck you're playing against. If you are against control with relic removal, svetya with her aegis (and making your deck full of aegis and massive buff) you want svetya.
On the other hand, if you can keep it alive (maybe you have face aegis, or they don't have removal) chains is absolutely amazing, especially if enemy has few aegis and large units rather than a go wide system.
In gauntlet, only one AI has fast play relic removal—Banish doesn't count. It is usually too late for the enemy once you get Chains on the filed, kill a few, and double your units stats. I've only had chains removed once. Given that chains is late game and AI tends to flood early in the decks that have relic removal, encountering relic removal is rarely encountered lest the enemy top draws. I've tried both Svetya and Chains, since both are in my Market. Svetya has only ever been overkill or fetched when I need her body. Wow, that sounded a bit lewd...
On the other hand, if you can keep it alive (maybe you have face aegis, or they don't have removal) chains is absolutely amazing, especially if enemy has few aegis and large units rather than a go wide system.