Well, I want to make a gmaul/blitz rusher. What should I train first? What are some good stats?
ok:
As Duch said, you should skill to make some money... to have a good rusher you should aim for about 10M to start.
To do quests, you should start by being a mage pure.
Get magic to around 70 however you can. preferably with combat so you get the hp as you will be soul warring later.
Then, you should quest attack however you can. Quests you absolutely MUST do:
Waterfall quest
Tree Gnome Village
The grand tree.
quests that are recommended:
Fight arena
look up attack rewards on runescape wiki and do the ones that don't give defense/prayer.
the bosses here should all be killed with magic.
Next, you should get attack to 40 (If it isn't there already) and strength to 50. there, you can continue training attack to 50 with brine saber (Or leaf bladed sword if you decided to get 55 slayer)
You should then soul war to 75 strength, and your hp should be around 50.
Alch to 80,
Stunalch to 82
Optional:
Get ranged to 85 with soul wars so you can brid/dbow rush too.
This is the basic gmauler at around 54 combat.
In the long run, you can get 94 magic, 94 ranged, 50/60 attack, and 92/82 strength, and 94 ranged.

