As funny as that sounds, I think Shalai is much better than Giver of Runes because Neoform is much more powerful than Chord.
My opinion is that both Call and Chord are unplayable in this archetype if we want to focus on competitiveness (there's a reason kiki-chord is a well-known clunky meme-ish strategy). In my experience, the bottleneck we encounter is mana on turns 2-5 (followed closely by the ability to close the game without a combo and through removal - but that's another discussion) and these cards are incredibly intensive in that regard for a deck whose only impactful creatures have CMC 3+ (usually wanting to grab Guardian/Kiki with tutors too).
On another note Collector Ouphe better than Kataki against Hardened Scales?
My opinion is that both Call and Chord are unplayable in this archetype if we want to focus on competitiveness (there's a reason kiki-chord is a well-known clunky meme-ish strategy). In my experience, the bottleneck we encounter is mana on turns 2-5 (followed closely by the ability to close the game without a combo and through removal - but that's another discussion) and these cards are incredibly intensive in that regard for a deck whose only impactful creatures have CMC 3+ (usually wanting to grab Guardian/Kiki with tutors too).
On another note Collector Ouphe better than Kataki against Hardened Scales?
GW Copycat
Jund Loam