This card is a mess:
Mana cost itself as Vija said is a mess; gold hybrid a la
Jund Hackblade or
Returned Pastcaller has already proven to be unappealing, having a new Phyrexian mana hybrid symbol not only makes it looks worse, it also negates the whole point of having the initial ugliness (which was to help make color intense gold cards easier to cast in limited without making them generic).
The mana symbol itself is bad too: like Phyrexian mana was already a bad idea, and this throws in hybrid for the hell of it.
Compleated keyword is interesting since it might open some potential for a "spells players cast cost an additional 1 life" but given the wording, this only works with Planeswalkers, which are the least common type in conventional set (e.g. not WAR).
Which brings me to the biggest offender in my opinion: the Mythic rarity. No Im not saying the actual effects should be rare or lower, but giving a keyword to a card type that only sees conventional print at the rarest rarity seems meaningless. And the whole point of making color intense gold cards easier to cast is to make them easier for one strategy to play in limited without allowing others to 'splash' them in; this is a Mythic that can still be played witlth only two colored mana instead of three.
Oh wow; I also almost forgot a flavor miss here: Planeswalkers cant be phyresicized. That was the whole thing in Scars of Mirrodin with Venser giving up his own spark to purify Karn, who at the time had given up his own spark during Time Spiral shenanigans and had already been tainted.