mtg split card Wizards Finally Changed the Rules Regardling / Fuse Cards copy the spell Split Second (the Card) :

Voja and Rin and Seri are once again popular homes for this

So this is clearly designed for one deck archetype, Life Gain, which is the third biggest archetype ever played, and it makes sense in +1/+1 counter decks that have the occasional lifelink dork or Commander or something that gains you life here and there like Akoum Refuge, and then if you have a Selesnya colored power matters build this would help there with things like Anthem effects

We still have Defiant Strike in this format, but we also have Gods Willing as a way to filter through cards and keep our creatures alive

What Happens When a Creature With First Strike Fights

Previously, expansions were released in sets of three, forming cohesive blocks that built upon each others mechanics and storylines

You can stop whatever you need to with this, but your opponent could end up better off for it just like with Chaos Warp and Wild Magic Surge