Tahm:
Passive, Tahm's attacks and abilities apply 1 stack, at 3 stacks abilities do bonus effects.
Pretty standard, nothing that special here.
Q, shortish range fast wide skill shot. Slows targets, at 3 stacks stuns instead.
About as basic of a cc skillshot as you can get.
W, At 3 stacks may swallow an enemy, making them untargetable but reducing movespeed. Can swallow an ally instead and increase movespeed.
Pretty interesting but not overloaded. You just make someone untargetable for a bit. Restricted vs enemies by passive.
E, damage taken partially restores out of combat. At the expense of this regen all damage taken in combat is converted to a shield.
Interesting, but just a different way of saying sustain and self shield that scales with hp.
R, bring an ally on a magical journey after a bit. Boosted dmg on everything.
Pretty basic, tf ult with an slly.
Now nidalee:
Passive, Q and W gives abilities bonus effects (dmg) and movespeed.
Comparable to tahm passive, enhances 2 abilities in less time with less reliability.
Q1, skillshot that gains dmg over distance. Marks target.
standard
Q2, auto reset, enhanced execute dmg increased by passive.
Also standard but that is 2 different abilities in 1.
W1, places a trap that lasts a long ass time, no limit. Traps deal dmg and mark target.
standard trap.
W2, short cd jump, can hop walls, long range targeted vs marked targets. In addition the cd is mostly reset on kills on ANYTHING.
High mobility, mobility resets, long ranged gap closer, pretty strong ability right there.
E1, a heal, that also gives a ton of attack speed.
Standard heal... on a poke/assassin champ. Also big adc buff.
E2, aoe dmg.
Not much to say, just dmg. Combined with a heal. Yeah.
R, swap forms. In addition passive resets ult cd completely in human form. Ranks in this rank up 2nd abilities.
Not as complex as Jhin passive, barely.