good stall with Obnoxious Celtic Guard would be Mage Power, My Body As A Shield and Dark Bribe.
4 Cards to be able to stall for up to 3-4 turns, that is if your opponent doesn't get Brain Control/Mind Control and synchro/tribute the monster. Less turns if your opponent has many cards that can deal with monster removal, more if he doesn't have that much. In basic, decks have Torrential, Lightning Vortex and Brain Control. On top of that there's DAD, Fissure, Smashing Ground, Dimensional Prison, Mirror Force, Ryko and a few other cards that are pretty much common in the meta.
In overall, good stall is what can help you long enough to your taste without actually needing too many cards. T-Roar is the basic many people use, because in the average good deck, 1 turn is usually all that's needed to make a come back.
For longer, as has been said, Level Limit Area B, Gravity Bind, Spirit Reaper, Marshmallon, Arcana Force 0 - The Fool, that way you have 2 S/T and 5 monsters in the deck that would stall. Add to this MBAAS, 3 Dark Bribe, Pot of Avarice, Swords and you got yourself a little basic that in theory can outrun a few decks.
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