I think dominate is their version of capture the flag

Classic Capture the Flag is when each team has a flag they guard and one they try to capture.  You capture the flag by grabbing it from the enemy base and running it back to your flag.  If you are killed you drop the flag.  If your enemy touches it it is returned to their base, but a teammate can also pick it up and run on with it from where you fell.  It doesn't count as a capture unless your flag is safe in your base when you bring the enemy flag back, so you want to focus on defense as well as offense.  Each time you capture you score a point and the flags are returned to their base.  The team which reaches three points first wins. 

Ever played Warsong Gulch in WoW?  That's CTF.  CoD4 Headquarters mode is a variation on CTF.

With Demigod it would be pretty cool to have this in, though you'd probably have to shift or remove some of the towers.  You get strategies which deal with protecting specific allies and killing specific opponents, and with a game like this it seems like it would be a shoe in, but maybe not.. 

It'd be cool if in a real CTF the flag spawned a bit in front of your citadel and towers had 15% hp, but regenerated 60 seconds after they're destroyed or so.

Or you have 3 areas of your base with flags protected with towers, and each time the flag is sucessfully captured the 2nd and 3rd flag would spawn in the new protected locations.

wouldnt unclean beast have a HUGE advantage in CTF? also warp items would have to either be removed, or cause the flag carrier to drop the flag before warping

Yes, CTF would be a great fit for the game.  I can already see teamwork involving a runner stacked with +speed, covered by a QoT with brambles and Oak throwing out a timely shield while TB is stunning and slowing interceptors.

 values = {
            {
                text = "<LOC lobui_0307>Conquest",
                help = "<LOC lobui_0308>Achieve victory by destroying the enemies Citadel.",
                key = 'conquest',
            },
            {
                text = "<LOC lobui_0557>Dominate",
                help = "<LOC lobui_0558>Achieve victory by gaining War Score through capturing and holding flags.",
                key = 'flagcontrol',
            },
            {
                text = "<LOC lobui_0559>Slaughter",
                help = "<LOC lobui_0560>Achieve victory by killing enemy Demigods.",
                key = 'slaughter',
            },
            {
                text = "<LOC lobui_0561>Fortress",
                help = "<LOC lobui_0562>Achieve victory by destroying the enemies Fortresses.",
                key = 'structuredefense',
            },
            #{
            #    text = "<LOC lobui_0563>Capture the Flag",
            #    help = "<LOC lobui_0564>Achieve victory by capturing the enemies Flag the specified number of times.",
            #    key = 'capturetheflag',
            #},
            #{
            #    text = "<LOC lobui_0128>Sandbox",
            #    help = "<LOC lobui_0129>No victory conditions.",
            #    key = 'sandbox',
            #}

I tried it though and seems they havnt implemented any functions for it, and to be honest I dont think it would turn out too good in demigod in its current state.