I've recently bought Skarner, and most guides tell me I should use movement quints. Unfortunately I do not have movement speed quints, what quints are a good replacement?

My runes are usually: Flat Armor Seals, MR per lvl Glyphs, AD Quints, and 6 AD Marks, and 3 Armor pen Marks.

It should be +24 MR at lvl 18, 13 armor, +12 Phys dmg, +5 Armor Pen.

Sometimes I do use OddOne's rune build tho, when I feel like I might need the extra MS. But the way I build my Skarner I don't really need it.

Attack speed. Will help lower your cds

get move speed quints.

Skarner really, really needs the move speed. Getting in melee range of your opponent is the hardest part of ganking with him. They're worth picking up anyway- there aren't many champs that don't benefit from them.

There really isn't just one right answer to this. With skarner you don't just set up one build and say "I'm done", you need to be ready to adapt to your team comp and what the enemy is doing. That said, if you plan on ganking pre lv6 the MS quints really are a must, especially if you plan on getting cloth +5 as your starting items. Otherwise, use the quints to fill whatever gaps are left by your masteries and other runes.

If your team is squishy get flat health quints. If your team is tanky, get Attack Speed or CdR. Flat mana regen or health regen can also be used if you don't trust your team to help you leash, but they are not ideal.

Move Speed. You absolutely need MS on skarnar or else you will have trouble initiating.