The new equalizer ruleset means that every monster gets the same health as the highest monster from either team.
NB HINT - you want to avoid playing high health monsters with this rule set because by playing them you're just giving an advantage to your opponent if they are playing low health monsters: if monsters have low health, they'll have other strengths to compensate).
To my mind this rule set favours death very strongly as there are lot of monsters with very low health (as seems fitting for a 'death' splinter), and all you need is to play one monster with decent health to boost ANY of these, or take the riskier stance of letting your opponent do the health boosting for you.
In terms of useful buffs I think the following are going to be extremely useful, which is all based on the fact that the ability to play lower health cards means you're probably going to see higher damage coming your way.
In terms of strategy, I think it's just set up a massive two tanks and then just pile in with as much damage as possible, I think snipe and sneak are risky for these potentially high health battles as it could take you a very long time to take anything out!
With her universal affliction, headwinds and universal void, she's a great starting point, and then combined with the low mana skeletal warrior as a tank (who will now likely have more than 2 health of course!) and 2 mana hexing-spirit, you've already got a good starting line up for just 4 monster-mana.
Here's a 99 Mana Battle in which I utterly decimate my opponent
Start
Finish
OK maybe it's a bit unbalanced, but then again if they are going to play high health monsters and gift my skeletal warrior another 9 health when he has shield, thanks! Note how my unicorn is now almost invincible against blast too.
Here's a 23 Mana Battle in which Mim0 hexed my opponent into having no chance of doing any significant damage to my tank..
Start
Finish
You can see from the start that they were never going to get anywhere, and by the end my opponent is now doing 0 damage to my tank while I'm doing 5 to him.
Interestingly he took out two of my cards with the blast ability.
You'll note I was expecting a lot of sneak attacks: this dude always uses fire, and they sneak pretty well.
Finally, equaliser nullifies the first strike benefit you get from opportunity - so no more ability to take out the weakest card - if they strike first, it'll always be the tank because of the equal health. Something to keep in mind.
Perhaps Mimosa would have won these battles anyway, but she does seem especially well-suited to this new rule set!
I won't show you the two battles I lost with this rule set where death wasn't an option! Still learning!