To replace the default spells, I'll start with one spell and work through my assumptions to see where it leads.

In Warrior & Wizard, the effect of the Blur spell is Blur makes it harder for others to see, hear, smell, etc. the target of the spell.  (It's Thrown, so it is applied to a target, which can include the caster.)  All attacks against the target are at a -4 penalty; any Perception Checks against the target of the spell are at -4 as well.

Here's the first of my assumptions. Checks in TFT-like games are rolling a number of d6s to be equal to or less than an attribute. Since most rolls are 3d6, I'll treat a -4 penalty to checks as a -4 penalty in The Black Hack.

The Black Hack uses Advantage and Disadvantage, usually regarded as a +4 bonus (Advantage) or -4 penalty (Disadvantage). So we'll translate the effect in terms of advantage and disadvantage. TBH uses player-facing rolls, so at least for attacks, it would be roll advantage on a DEX check to avoid damage in combat. As far as opponents Perception checks, I never really ran into that playing TBH. Still, it's just as easy to say that the player rolls with Advantage on DEX checks to avoid others perceiving physical details about you.

Okay, we have one spell effect for my Black Hack with Different Magic system underway.