Easiest way to beat the game on hardcore after you realize how annoying non-stop dodging is with Kat...
New strategy:
skills (forgot the names sorry)--
pts into all heal skills..flame aura heal, bigger heal in the actual heal skill, bigger shield for the shield, and get all heal talents...
also get the gain focus for crits thing..even with a low crit rate it performs well
also I put pts into slow pillar thinking it would keep them in it, but in practice they either stay in place (either ranged or fighting Lucas, hound, or you), or they are too fast to hit at all. I would go with damage next time
items--
prioritize stamina/armor/block
get vamp when possible
Stand still, cast flame aura or empowered flame aura and hold block...charge free power orbs and cast emp. pillar while healing billions per second. You can tank nearly every boss' best shot repeatedly, exceptions being unblockables, but these are too weak to kill you anyway so there's still no danger to standing still blocking. I could tank the corrupted dudes orb shots if at full focus w/ a shield up (it seemed glitched however and sometimes I would get knocked down and killed anyway...but when this didn't happen I only lost ~40 focus). The free orbs charge VERY fast so you actually get more offensive dps from blocking -> emp. <some skill> then you would dodging and using more of a glass cannon build imo. Even if that's not true, it has to be reasonably close...and there's the bonus that it's a far less annoying play style and far more survivable (therefore probably faster with no reloading).
How to level...
Damage is king in the beginning. Don't be fooled by agility at level 3. 3% more crit when you do 4 damage is worth less than 3 more damage. ALWAYS pick the item that gives +attack in the beginning. Some people also don't seem to realize this ALSO adds to ability dps (they are summed, except for defensive abilities..."generally"...according to the help). This means +2 atk beats +2 will. If you want to fly through the early stages, get huge attack and press spin kick a lot... If you also have good stamina and armor, you can use human empowered normal attack which should pretty much one-combo-shot any group or mini-boss while letting you live through it, or if you won't survive, use the flame form empowered attack from range (also seen posts that not everyone knows about empowered normal attacks...someone asked about the "big fireball" of Anjali...hold shift and left click...cost one orb...it is this fact alone that makes block amazing...pick Lucas, block stupid crypt caster orb, emp strike them to hell)
Stamina is also king relative to armor like damage vs crit. A little bit of mitigation is worth less than 7 stamina when you have 70 hps...7 stamina doubles your health! ALWAYS pick +stamina in the beginning. Don't be fooled either into thinking it's easy because it's the beginning. You waste just as much time dodging around for 90 seconds trying to defeat an "easy" mini-boss as you do with the same tactics later on. Far better to just tank for the orbs and fight back with purple strikes. Here's some math: if you have 100 hp, getting hit for 20 is very bad. Say their attack speed makes it 6.8 dps. You only heal 1/4 of the damage you take...I think it's one heal per sec over 30 seconds for half health? 50hp/30sec = 1.7hp/s). This means you take 3/4 of the damage or 5.1 dps, and will die in ~20 seconds. If you have 200 health, you heal for 3.3 or 1/2 the damage AND it takes twice as long to kill you to begin with. You will die in 200/3.3 ~60 seconds. You have 3x the survivability with double the health! This non-linear relationship continues with improved skills, vamp, armor, etc. until you never die despite finite health.
However...damage taken goes down with increased damage dealt...if you kill the guy killing you twice as fast you take half the damage...if you were soloing. Between free orbs from damage taken (blocked or not) and your partner, you get a significant amount of free damage such that it's not a direct tradeoff with more "normal" damage output = less damage taken. This further boosts the usefulness of survivability over glass-cannonility. You proportionately don't gain as much damage by getting more damage as you lose in life by not getting more life.
Now, when you have a lot of health and deal a lot of damage, eventually there are trade offs...usually the most expensive item you just found is clearly best...e.g. you have 1500 health, and by losing 3 stamina you gain 40 will or something. While the goal of heal-tank is to primarily survive, don't be afraid to build well-rounded. You want damage too and if you continually upgrade from stores and drops you will have solid all-around stats.
So, to have permanent-block-invincibility-mode, you need armor and block. Armor reduces the damage to the point where block can block it with no focus lost. You actually wouldn't need stamina, and because of things like vamp or heal from damage (will based?), armor+block provides a multiplier for whatever health you do have...each hp healed is "more" than a plain unarmored hp. You still want stamina for unblockables, mistakes, some things hurt even when blocked, and some heals are % health based. It's also easier to find rounded stat items than specifically armor+block, but the point here is late game, when you have lots of everything, you probably will do well to get more armor+block+vamp+will than that little bit extra health or crit or whatever.
Lastly, to emphasize block=orb, some people mentioned Lucas has difficulty w/ first boss in caverns. Wat? Keep your focus up, dodge into her electric aura thing, charge orb, dodge out, emp. strike. Repeat 10x and win. Block her spread nuke. Block everything. Seriously, next person that dodges more than once in a row must uninstall. Dodge is for everything that can't be blocked, which is almost nothing. Therefore one should rarely dodge. It is unfortunately necessary with Lucas in the above example because you will get immediately knocked away before you can block in the first place...but in general, if you are dodging, you are probably meaning to block.
Btw this heal tank strategy of course applies very well to Lucas with his improved heal skill and victory rush and his shield item slot and all that.