Mako Deck - Suijin or Levia

Levia using Mythic Depths and running 3 A Legendary Ocean since they are treated as Umi

I actually use 2 Suijin and 1 Levia in my deck with Mystic Depths as Mako. The deck also consists of 3 Anglers, 1 HT Gyojin, a Kaiser Sea Horse (really helpful when using BWSW), 2 BWSW, an extra Umi, and some filler monsters and spells (no traps) to cycle through cards, like Card Trader.
The Suijin give a nice delay when I can't get my one Levia out and by the time I can get him out I just use his effect and attack once to win.

its based on play style. If you sit back on the defensive more, Suijin is a better stall monster with high DEF and effect. My opinion: the current meta has too many things (order to charge, enemy controller, etc) that render an agressive offensive style more effective. Thus, if you can choose i would go Levia.

I run Mako b/c my first investment was in Age of Discovery. Its a fun deck, but probably won't get KOG. (maybe plat 1?). Biggest advice - keep it focused and to 20 cards. I run 2 levia, 2-3 waves, and then 3 anglers, 3 HT gyojin, and whatever you can afford with yomi ship and moray eel. After that, tech cards like michizure, Interdimensional Transporter, winds of etaqua are all you would have or could get by levelinng up kaiba and mai. They work great with this deck. Then if you have ECon or Kuriboh, they help counter your opponent's counters.

This is my Mako deck:

Skill:
Mythic Depths

Cards:
2 Levia-Dragons
2 Suijins
3 Piercing Morrays
2 Needle sunfish
2 Yomi ship
3 unshaven angler
3 high tide gyojin
1 riryoku
1 twister
2 big wave small wave
1 despell
1 (extra) Umi
2 Michizure
1 Magical arm shield
1 adhesion trap hole
1 trap jammer

Hope this helps

Just wait for the next support card come. Their this card called(A Legendary Ocean) Field spell that reduce all water monster level by 1. That make level 7 like Levi/Suji a 1 tribute monster. Its gonna be UR to leaks.

Theirs card called Maiden of the Aqua can be use as stall with 2000 deff and the card act as Umi. So if you already use a umi you can use her to active effect like Ocean Dragon Lord Neo-Daedalus or Levia. She doesn't not increasing att/deff.

Warrior of Atlantis a 1900 beater cards goes to 2100 with umi and has a effect to search in deck and get out Legendary ocean by tribute itself.

I would recommend investing for a third levia for the future if you want to upgrade the Umi deck. But you don't have too.

When all these cards for Umi deck come out. Its gonna be a good investment. So save up gems for these coming cards.

Levia and run an extra Umi in your deck

I think that Levia is better if you can easily summon it (by using Big Wave Small Wave, or water hazard and unshaven angler) and if you want to attack aggressively your opponent by destroying all of his cards and not letting him destroy Umi.

Or, you can also use Suijin (use Stray Lambs or the same cards that I've said above) to play defensive and get easily the cards you haven't drawn yet.