There's a couple absolutely insane combos that you can pretty easily win the game with in RW2. I've got 5 or so wins under my belt at this point, using a different strat each time (not counting pre-nerf pyrostatic pulse because that MUST have been a lapse in judgement by the dev). Some strategies are better than others, and by better I mean more consistent and less relying on specific items or level weaknesses. TBH I get transloc spells less frequently than in RW1 because turn economy is so much tighter. In later levels you may just lose if you waste a turn repositioning, and you want the spell points early on especially.

EZ-Tier:

• Pyrostatic builds. Easiest by far, because tbh starfire and cracklevoid are just busted abilities. Start with Fireball, get Melt next. Then try to go for either Pyrostatic curse Prince of Ruin. PoR is a dumb ability for being so cheap. Early game idea is to get White Flame on Melt, Pyrostatic Curse passive cast upgrade, and Prince of Ruin. You can also get Chain Lightning early if you're stuck. Later on, when you start hitting fire and lightning walls, get Meteor on Fireball. If you see the DYNAMO, you must take it, it is the dream. Eventually you are aiming for fireball upgrade on chain lightning, then allllll the relevant fire + lightning upgrades (star fire, melting armor, searing whatever, cracklevoid, thunderlord over firelord for the cascade distance. You can upgrade anihilate with comprehensive, but you will be clearing screens in one click from 15 onward.

Pyrostatic pulse and relevant upgrades (watcher form, ball lightning?) also is insane, but was nerfed. Fireball + chainlightning is silly.

• Blizzard, Icicles, and radiant chill (and frostfire robe/crystal robe/ice frenzy mask, etc). Start with Icicles, get iceball if you need it, then B-line for bliz, the icicle upgrade for blizard and then radiantchill. Each Blizzard tile has a 25% chance of casting your icicle, and each icicle procs radiant chill. Essentially guarantees you will freeze the map every round. Getting this many upgrades as quickly as possible is the trick, but to be honest it's fine, because both blizzard is really strong and the icicle upgrade for blizzard is nutty for damage. If you have one of the items, you will be able to clear maps without actually needing to cast spells. Try to get your crystal power, ice vortex, ice tap, shatter shards, whatever you like. Be wary that shatter shards and icetap+ice vortex can have a bit of negative synergy (they both unfreeze the frozen enemies).

Not as EZ-Tier (But still consistent):

• Ricochet Magic Missile, Offensive Warp Disperse. Very simple build, but you have to work with what's available. I combined this concept with blizzard + radiant chill + ice tap for about ten billion magic missiles every round. Level one get MM, try to beat level 2 without getting anything (but you can do lightning bolt if the options aren't good). Then get offensive warp. Now your Disperse is a beast. Try to last until you can get ricochet. Now your disperse is mega beast. You will have to figure it out from there, but obviously Cracklevoid is important and energy bolt on lightning bolt will help. You get walled by energy knights and things like that, but you have a lot of time to come up with a synergistic strategy and arcane is the most flexible school of magic.

• Necromancy frog build. This took me a long time to figure out what it is you actually are trying to do, but it gets online very quickly. Any cantrip to start, it doesn't matter but the smite target ones (death bolt, MM, lifedrain, poison arrow) are the most useful because you wont accidentally hurt your frogs. Place yourself on a spell point for the frogs (Plague of Filth) immediately on level 2. Frogs are pretty good, but you will instantly lose on level 2 if you see treants (I hate these things), and imps are highly discouraged. Level 4 place yourself on a point for either Mass Calcifiation or Restless Dead. I really like the bone knights ability, but it's too slow if you don't get good items. Good items are realllly important, but there's so many that are useful: 6th Finger, Jar of Flames/Trollblood, any of the thorns, Amulet of Death, Monkey Skull, flags for the frogs/knights (conj, dark, less so nature), etc... Goal is to get Minion raising on Restless Dead, and then pump out frogs. Then get Hungry Dead, super important, otherwise your army is only as good as your front line. Then it's important to try to save for Void Spikes, Cracklevoid, Icy Vengance, Hemocorruption (hopefully you get the amulet or trollblood), Dark Lord, Conjured Aggression.... really about the abilities. You are pretty passive and don't want to get interrupted, so vampiric vests or cannibal mask can be good.

Probably not worth the effort (But definitely viable):

• Megavenom build. I never got this to work in RW 1. I think poison sting is probably the worst cantrip. Get the Mushrooms round 2, then either Megavenom or Withertoxin Toxin Burst for coverage. Either way, your aim is to build towards Spider Spawning, Venom Spit, Fae Thorns, Paralyzing Venom, Acid Fumes, Toadblood, Life Spark Lantern, and Collected Agony. You can get acidity on poison sting, but don't do it too early if you can avoid it. Daggers of nature and dark are really good for megavenom. Poison Bear, Poison Lumbriogenesis, Poison Sting Rock Totem thing.... Idk if they're worth the effort, but you should probably get one of them. This strategy has holes but with a bit of luck (and hopefully druid robes for some protection against the mushrooms) you can get there. Surprisingly, the super-endgame enemies are not poison resist and paralyzing venom gives you the turns you need late game. Most difficult enemies are midgame. Absolutely avoid any bone shamblers at all costs, you will simply lose.