[Mitchell]

Okay so i have figured out how to make-shift cast spells:

Find the spell book and set the spell index and charges:

		while ((ent = FindEntityByClassname(ent, "tf_weapon_spellbook")) != -1)
		{
			if(ent)
			{
				if (GetEntPropEnt(ent, Prop_Send, "m_hOwnerEntity")==client)
				{
					SetEntProp(ent, Prop_Send, "m_iSelectedSpellIndex", spell);
					SetEntProp(ent, Prop_Send, "m_iSpellCharges", 10);
				}
			}
		}

Possible spells:
0 Fireball
1 Missile thingy (bats)
2 Ubercharge
3 Bomb
4 Super Jump
5 Invisible
6 Teleport
7 Electric Bolt
8 Small body, big head, speed
9 TEAM MONOCULUS
10 Meteor Shower
11 Skeleton Army (Spawns 3)
I used tf2 items to give my self a spell book, it is needed to cast spells.

SpawnWeapon(client, "tf_weapon_spellbook", 1069, 0, 0, "");

Spoiler

I found this to spawn the weapon.

stock SpawnWeapon(client,String:name[],index,level,qual,String:att[])
{
	new Handle:hWeapon = TF2Items_CreateItem(OVERRIDE_ALL|FORCE_GENERATION);
	if (hWeapon == INVALID_HANDLE)
		return -1;
	TF2Items_SetClassname(hWeapon, name);
	TF2Items_SetItemIndex(hWeapon, index);
	TF2Items_SetLevel(hWeapon, level);
	TF2Items_SetQuality(hWeapon, qual);
	new String:atts[32][32];
	new count = ExplodeString(att, " ; ", atts, 32, 32);
	if (count > 0)
	{
		TF2Items_SetNumAttributes(hWeapon, count/2);
		new i2 = 0;
		for (new i = 0;  i < count;  i+= 2)
		{
			TF2Items_SetAttribute(hWeapon, i2, StringToInt(atts[i]), StringToFloat(atts[i+1]));
			i2++;
		}
	}
	else
		TF2Items_SetNumAttributes(hWeapon, 0);
	new entity = TF2Items_GiveNamedItem(client, hWeapon);
	CloseHandle(hWeapon);
	EquipPlayerWeapon(client, entity);
	return entity;
}

I will probably make a plugin to change/cast spells on players.
Still trying to figure out how to show the "current spell" on hud. lol.