Or hey, just pay the white and four generic mana, and ultimate away one planeswalker from another ones loyalty stash
A permanent is removed from combat if it leaves the battlefield, if its controller changes , if it phases out, if an effect specifically removes it from combat, if it's a planeswalker that's being attacked and stops being a planeswalker, or if it's an attacking or blocking creature that regenerates (see rule 701.12) or stops being a creature
It exudes the luxury of the Avishkar apartment where our subject resides and were unsure if its the Guild or her latest hit
For example, if you cast Junkblade Bruiser (a creature with a mana value of 5 and an ability that triggers whenever you expend 4) by paying its full cost of five mana, you'll already have spent four mana on spells before Junkblade Bruiser enters, and therefore its ability that triggers whenever you expend 4 won't be able to trigger at all that turn