You want to stick to 2 colours for now. You have too many random units like lonqu Ike BK Navere are too situational.
The +30 effects are extremely hard to pull off and at times over kill.
Marth5 is way too slow. if you are not promoted by turn 3 you will lose the game. Also Marth can buff himself "all allies" Include themselves. "all other allies" dont.
Fliers win games. if not fliers use archers. Almost half you deck should be these.
A good skeleton is 8-10MC ( with the 3 or 4 drop being the main card you want to promote and sit on) 4-8 healers 16-24 units used for support value (fliers and archers The rest with easy threats or utility such as gerome, nowi , linde, merric, caeda
This is For a marth MC
As for Ike as MC. He works best in a mono green Deck. Soren Elincia Mist are good core cards to have.
Also we have a Metagame discussion and competitive decklist thread. Please check that out for Competitive decks and advice.